How To Display Percentage In Pandas Crosstab

By default computes a frequency table of the factors unless an array of values and an aggregation function are passed. Array of values to aggregate according to the factors. So we have seen both Pivot table and crosstab works perfectly fine with any data and can be used to quickly build the pivot table using the data.

Only thing you have to keep in mind that crosstab works with series, list or dataframe columns but pivot table works with the entire dataframe. Also the normalize function in crosstab is quite useful when you have to find the percentage or normalize the data across the rows and columns. If you don't like the output of the Chi-square test, see the section Chi-square test of independence using custom function. The function does not require a dataframe as an input. It can also accept array-like objects for its rows and columns.

The function can normalize the resulting dataframe, meaning that the values displayed can be displayed as percentage of row or column totals. Pandas offers the crosstab function that offers loads of customization, similar in many ways to Excel's pivot table. In its most simple form, feeding pd.crosstab an index and a column will return counts of the index/column's appearance in your dataset, like below. Honestly, not the most interesting nor the most useful. This is where the pd.crosstab's other parameters really amplify the power of crosstabulation. The percentages are rounded to 2 decimal places while the Chi-square value and the p-value are round to 4 decimal places.

Pivot table lets you calculate, summarize and aggregate your data. MS Excel has this feature built-in and provides an elegant way to create the pivot table from data. In this article we will see how to use these two features and what are the various options available to build a meaningful pivot and summarize your data using pandas. Explanation of pandas crosstab function how to use it and some of its features. Pandas offers several options for grouping and summarizing data but this variety of options can be a blessing and a curse. These approaches are all powerful data analysis tools but it can be confusing to know whether to use agroupby, pivot_tableor crosstabto build a summary table.

Since I have previously covered pivot_tables, this article will discuss the pandas crosstabfunction, explain its usage and illustrate how it can be used to quickly summarize data. My goal is to have this article be a resource that you can bookmark and refer to when you need to remind yourself what you can do with the crosstabfunction. The example above is the simplest kind of contingency table, a table in which each variable has only two levels; this is called a 2 × 2 contingency table.

In principle, any number of rows and columns may be used. There may also be more than two variables, but higher order contingency tables are difficult to represent visually. The relation between ordinal variables, or between ordinal and categorical variables, may also be represented in contingency tables, although such a practice is rare. For more on the use of a contingency table for the relation between two ordinal variables, see Goodman and Kruskal's gamma. Pandas crosstab comparison with pivottable and groupby Like many functions that compute grouped summary statistics crosstab works with categorical data.

Crosstab always returns a dataframe and below is an example. Heatmap shows again that in the dataset for each color code the number of ideally cut. Like many functions that calculate group summary statistics, crosstab () can handle categorical data. It can be used to group two or more variables and perform calculations for a given value in each group.

Of course, use groupby() or pivot_table() can do this, but as we'll see later, crosstab() brings many benefits to your daily workflow. Cross tabulation is a method to quantitatively analyze the relationship between multiple variables. It will help to understand the correlation between different variables.

For creating this table pandas have a built-in function crosstab(). Its a tabular structure showing relationship between different variables. The Pandas crosstab and pivot has not much difference it works almost the same way. The only difference that I see after going through the source code is Crosstab works with Series or list of Variables whereas Pivot works with dataframe and internally crosstab calls pivot table function.

So when you have list of data or a Series then you should use crosstab and if there is data available in a dataframe then you should go for pivot table. Now, we can perform this same operation using the crosstab() method. Same as before, we want our returned index to be the unique values from day and our returned columns to be the unique values from sex. Additionally, we want the values inside the table to be from our total_bill column so we'll set the argument values to be df_tips['total_bill']. We also want to calculate the mean total bill for each combination of a day and gender so we'll set the aggfunc argument to 'mean'.

Get code examples like how to display percentage in pandas crosstab instantly right from your google search results with the Grepper Chrome Extension. The pandas crosstab function is a useful tool for summarizing data. The functionality overlaps with some of the other pandas tools but it occupies a useful place in your data analysis toolbox. After reading this article, you should be able to incorporate it in your own data analysis.

The crosstabfunction can operate on numpy arrays, series or columns in a dataframe. For this example, I pass in df.makefor the crosstab index and df.body_stylefor the crosstab's columns. Pandas does that work behind the scenes to count how many occurrences there are of each combination. For example, in this data set Volvo makes 8 sedans and 3 wagons. In crosstab(), you can also use row and column names to change indexes and column names directly within a function. These two parameters are very useful when we group multiple variables at a time, as you'll see later.

You can even rename the row and column names of this cross tab. For this, you have to pass rownames and colnames parameters to the crosstab function. In the data analysis part, we need to calculate some statistical measurements.

For calculating this pandas have multiple useful functions. The first useful function is describe() the function it will display most of the basic statistical measurements. For this function, you can add .T for transforming the display. It will make it easy to look at when there are multiple columns.

In crosstab (), you can also use row and column names to change indexes and column names directly within functions. These two parameters are very useful when we group multiple variables at once, as you will see later. Pandas crosstab can be considered as pivot table equivalent . It shows summary as tabular representation based on several factors. The information can be presented as counts, percentage, sum, average or other statistical methods. We will now use this data to create the Pivot table.

Before using the pandas pivot table feature we have to ensure the dataframe is created if your original data is stored in a csv or you are pulling it from the database. Read this post to find out how data can be imported and merged into a dataframe using pandas. In each of these situations different programs give different results. The two tables below are computed using data where everybody in the data has selected at least one category.

And, as will occur with all of the standard programs, the results are the same. That is, the percentages on the table on the left, which has been computed using Q, are the same as those on the right side of the second table, which was computed using SPSS. Generally, summary reports will show tables of percentages for categorical variables, such as age and gender, and tables showing averages for numeric variables.

For example, in the summary report from MarketSight below we can see that the first table shows an average of a numeric variable and the second shows percentages and counts from a categorical variable. A simple pandas crosstabThe values parameter allows you to set the variable to tabulate over. For example, the dataset I'm working with is 1 month of WMATA ridership data, with the ridership volume summarized by station origin and destination, by time of the day and of the week. A far more useful crosstab would be look to at the number of rides taken during time of the day and day of the week. The aggfunc allows you to specify the operation that applies to values. If aggfunc is specified, then values must also be specified.

A key benefit of the crosstab function over the Pandas Pivot Table function is that it allows you to normalize the resulting dataframe, returning values displayed as percentages. Tab has a number of options that allow for different kinds of analysis. Row calculates the percentage of the row that each cell constitutes.

Col does the same for columns, and cell works for the overall table. Tests of independence between the two variables can be performed with the chi2 option (among some other available tests; see the help file). It cleans up the output, ability to calculate row/column percentages, and has the ability to export the results to a csv file. We just learned that there are 891 rows in the dataset. In an ideal case, we should have 891 data in all 12 columns. If you notice the first five rows of the dataset, there are some NaN values.

The table allows users to see at a glance that the proportion of men who are right-handed is about the same as the proportion of women who are right-handed although the proportions are not identical. The strength of the association can be measured by the odds ratio, and the population odds ratio estimated by the sample odds ratio. If the proportions of individuals in the different columns vary significantly between rows , it is said that there is a contingency between the two variables. In other words, the two variables are not independent.

If there is no contingency, it is said that the two variables are independent. Alternatively, given the crosstab output above, you can present it in a different format that may be easier for further analysis. For example, the resulting summary tables in SPSS and Q are shown below. Some crosstabs do not clearly label whether percentages are row or column percentages (e.g., the example below). When reading a table, the easiest way to check if it is showing row or column percentages is to check to see which direction the numbers add up to 100%.

In the table above, the percentages add up to 100% in each column and, furthermore, this is indicated on the table by theNET, and thus it shows column percentages. The pandas crosstab function builds a crosstabulation table that can show the frequency with which certain groups of data appear. First DataFrame is always the crosstab table with either the counts cell row or column percentages.

To improve the look and feel of our table, we'll append percentage signs to each cell in the cross tab. In order to do so, we'll first convert the crosstab contents to a Python string data type. We then append the % character using a simple lambda function.

We can extend the cross tabs by passing a list of columns. Here we've passed in two dataframe columns for the crosstab rows and a single column for the crosstab columns. Tabulate the data in the Origin variable, which shows the country of origin of each car in the data set. Convert the resulting cell array tbl to a table array t. Create a frequency table that shows, in its second and third columns, the number and percentage of patients in the data set that have a particular height. Display the first five entries and the last five entries of the matrix that tabulate returns.

Tbl contains one row for each height between 1 and 72 inches, where 72 is the maximum height value in Height. The Chi-square test of independence tests if there is a significant relationship between two categorical variables. The test is comparing the observed observations to the expected observations. The data is usually displayed in a cross-tabulation format with each row representing a category for one variable and each column representing a category for another variable.

This means that one will not be able to tell which levels of the variables are responsible for the relationship if the Chi-square table is larger than 2×2. If the test is larger than 2×2, it requires post hoc testing. If this doesn't make much sense right now, don't worry.

Further explanation will be provided when we start working with the data. A scatter plot is used to observe and show relationships between two quantitative variables for different category items. Each member of the data set gets plotted as a point whose x-y coordinates relate to its values for the two variables.

Below we will plot a scatter plot to display relationships between Age and Amount_spent columns. To show unique values count we use value_counts() method. This function will display unique values with a number of each value that occurs. For example, if we want to know how many unique values of Gender columns with value frequency number of then we use this method below. If we want to display single or multiple columns data, simply we need to pass column names with a data frame.

To display multiple columns of data information, we need to pass the list of columns' names. The most elegant way to find percentages across columns or index is to use pd. crosstab . Just specify the index, columns and the values to aggregate. The normalize keyword will calculate % across index or columns depending upon the context. Finally, note that in pivot_ Both table () and crosstab () have a dropna parameter.

How To Soften Hard Ground For Digging

Amending your soil properly can overcome heavy, compacted clay and get it back on track for healthy lawn and garden growth. Adding materials such as organic compost, pine bark, composted leaves and gypsum to heavy clay can improve its structure and help eliminate drainage and compaction problems. Heavy or hard soils contain a high percentage of clay and low amounts of silt and sand, resulting in compacted soil that becomes difficult to till. This proves especially true when the clay soils become devoid of organic material, which lightens soil texture by preventing all of the clay particles from sticking together. Improving a clay soil lawn or garden by adding decomposed organic material, such as compost, not only improves workability but increases fertility.

Cover crops, also called green manure crops, help loosen clay or compacted soils with their roots and by adding organic matter. They also prevent nutrient loss and erosion during the non-growing season. Leguminous cover crops, such as winter rye, alfalfa, hairy vetch and clover, which add nitrogen to the soil, are usually planted at the end of summer or early fall. When I first start a garden and double dig my rows (3' wide minimum) I will add DECOMPOSED organic matter and fertilizer and mix sorta kinda. Without using anything else this makes raised beds.

Sometimes there is a lot of moisture in the soil but it will look dry to you. My beds for plants are always ALWAYS raised with trenches at the bottom of the slopes to take excess water away to where ever I dictate. No matter what kind of soil I have, I make these raised beds. They start out a couple of feet high with the fluffy soil and then they are formed and compacted to get rid of large air pockets.

While wet earth by itself isn't easy to dig, one can use how moisture affects the dirt to their advantage. Damp earth can clump up, become heavier, and stick to the blades of your shovel. However, clay soils hard on the surface can break up after digging 10 inches into the ground. This wetting process underneath the top layer of earth allows you to lift entire earth pillars with a post hole digger easily. Gypsum is easily applied to the soil surface with a regular lawn spreader. It's an ideal amendment for improving soil structure and relieving compaction in existing lawns and gardens.

When using this method, adding a layer of an inch or two of sand or gravel on top of the clay will allow plants that cannot normally grow in clay to thrive. This is because some or most of their root system is above the clay soil, but the tips of the roots can still pull nutrients and water out of the clay. Common soil amendments include compost, grass clippings, straw, shredded leaves, rotted manure and dried seaweed.

Compaction is most likely to occur with heavier soils like clay and loam, but when heavy equipment is used, sandy soils can become compacted. These are soil particles that are packed closely together. The problem may be compounded by events that have happened to the soil over the course of years. The pore spaces are reduced to the point that air and water cannot move freely and plant roots cannot grow easily into the surrounding soil.

The soil could remain overly wet longer than is healthy for the plants growing there. Avoid adding sand or peat moss to clay; they can make those problems worse. In a garden bed, the best way to introduce organic material without digging , is to apply layers on top and let nature do the work for you. Simply pile your garden bed high with organic material – it can be wood chips, shredded paper, straw, chopped leaves, lawn clippings – whatever you can lay your hands on. It might be slow, but the wait will give you time to get to know your land before you plant. Instead of gypsum, consider core aerifying in spring, summer or early fall to reduce the compaction and improve plant health.

Aerifying with large half-inch hollow tines and punching about 25 holes/square foot will produce good results. Very compacted soil can benefit from several corings each year . This does not minimize the benefit of have a high Ca and Mg level reading in your soil test, but coring does physically reverse a physical compaction of soil particles. Yes, coring is an expensive service to buy, and most lawns really don't need it; but it won't hurt. And if the soil is compacted, it's usually the best solution to the stifled growth.

Walking on your lawn or garden when its wet is a common cause. Heavy, beating rains also drive clay particles together. Salts from fertilizers and winter de-icing solutions build up in heavy clay as well. Once you have realized your soil is compacted, there are several things to be done. Resist the urge to routinely roto-till or cultivate the garden. Instead, consider adding organic matter by using mulch or compost over the top of a flower bed or simply hand-spade it into the top 3 to 6 inches of soil.

For a vegetable garden, put 2 inches of compost on the soil surface and till in and repeat for a total of 4 inches in a season. A goal of 5 to 15 percent of organic matter would be advantageous. You will need to work at it over the years by repeating the process though.

Baked clay is almost impossible to break up, rotivate or dig, it's easier to spread the organic matter and grit and wait until the worms have done some of the work for you. To soften the hard soil, start by breaking up the top few inches as much as possible. Once you have raw broken soil, add a layer of compost, mixing it in with the broken up hard soil. Adding small amounts of water can also help to soften the soil, making it easier to dig and install a different landscape edging option. Your soil test or extension agent can help you determine the right amount of organic matter for your soil. In following years, build on your efforts by adding 1 to 3 inches of organic mulch as a topdressing each year.1 As it decomposes, it continues to gradually improve clay soil.

Adding sand can be tricky and typically is not recommended to be added to clay soil. A slightly faster option is to cover the soil with material that is full of soil microbes, as these will speed up the process. This includes compost, worm castings, and manure – and less of the dense, harder materials such as wood chips, which take longer to decompose. Make sure to cover this 'active' compost etc with a layer of straw mulch to avoid it drying out as this will kill the useful microbes, which don't like hot sun. Deep watering once a week will also keep things moving. After about a month you'll notice a difference and, if you keep feeding your soil every spring and autumn, it will soon be full of life and all your plants will thrive.

The addition of lime can raise the soil pH to excessively high levels, reducing the availability of plant nutrients and leading to poor plant growth. Advertisements for gypsum often claim the addition of gypsum will help loosen heavy, clay soils and improve soil drainage. Clay's potential as one of the best soil types for plant growth lies in its unique properties. Managed well, clay soil typically requires less irrigation and less fertilizer, and leads to healthier plants all around. Most heavy clay soils benefit from the addition of gypsum. It adds some nutrients but, more importantly, it loosens clay soils and makes it more workable.

Spread about 3 to 4 pounds of gypsum per 100 square feet over garden soil after it has been dug in the winter. Work it into the soil or allow it to be washed in by rain. Do not add sand to clay soils, as the small particles in clay bind with the sand creating dense soil that compacts easily. The weight of your footsteps can easily compact wet soil. Aeration should be part of every homeowner's lawn maintenance plan, but it is particularly important for residents of DFW. Aerating twice a year will keep the easily compacted clay soils of DFW loose and porous for optimal plant growth.

Ideally, DFW lawns should be aerated once in the spring and a second time in the fall. Commercial products, such as ClayMend, are also available to amend clay soil by introducing beneficial soil microbes and supplying them with nutrients. The company states that a blend of organic acids gathers ultra-fine clay particles and then microbes work to secure them together. This process opens the soil, allowing it to breathe. The beneficial microbial activity increases and plant roots are able to establish themselves in the restructured soil.

Nutrients that have been locked away become free to be attached to the organic material and the clay structures for easy access by the plant roots. Routinely scattering organic matter over the soil surface is the best long-term fix for clay or soil compaction. Without any further help, soil organisms will incorporate the organic matter and begin to loosen the soil.

Whatever hasn't rotted down by then is put on the compost pile. Worms will have carried their castings up through the soil beneath the trash and it will be fine, clear tilth. For a large vegetable garden, another solution is to grow a cover crop at the end of the season, then mow and turn in the following spring before planting.

The roots penetrate the compacted soil and loosen it. By mowing and turning the mowed tops in, the soil is additionally loosened. Cover crops could include annual ryegrass, winter wheat, winter rye, buckwheat, oilseed radishes and hairy vetch. About half of a healthy soil is made up of mineral particles like sand, silt and clay plus organic matter. That is the room for air and water movement around the mineral particles. Pore space is required in order to have a healthy environment for plant roots and beneficial microorganisms and earthworms to break down plant residue into organic matter.

And that is the last time I will mess with the soil of my beds expending lots of calories on my part. Also, by dumping a couple of inches on top of your beds, whether veggie garden or landscape ornamental beds, is the best way to get rid of weeds. I can't stand to take extra steps, do things that are unnecessary. A quick test is to push a steel rod or long screwdriver into moist soil – if you can't push it very far you may have compacted soil. To confirm, dig a 30cm-deep hole and slice a layer off the side for a closer look. Looser soil separates easily, while compacted soil is smoother and more solid – and often has visible horizontal layers.

You might even see plant roots growing horizontally along the lines, unable to break through. Clay's small particles make it hard to dig through, but they also allow it to hold water much better than sand or silt. So if you want to soften your clay soil for digging post holes, give it a thorough, deep watering. Walking on your lawn once it has been tilled and yet to dry will often result in compacted soil or hard soil. Even though most soils will harden under heavyweight, soil rich in clay is more prone to hardening because of clay soil's low drainage and tiny soil particles.

By taking steps to improve and maintain your heavy clay soil, you can enjoy all the benefits clay offers and reap the rewards of healthy soil and plants. Penningtonis here to help you overcome lawn and garden challenges and grow the best lawn and garden possible, in heavy clay and every other soil type. If you're planning to put in a much longer fence line, soften the soil by digging pilot holes 6 to 10 inches deep then fill each with water from a garden hose. Allow the water to percolate down through the soil before attempting to dig out the hole using a post hole digging shovel, also called a clamshell shovel. Garden centers and lawncare services often advise applying gypsum to your lawn to "decompact" a hard soil. This is supposed to accomplish softening by improving the structure of the compacted clay soil.

With the exception of the arid western United States and our coastal areas , adding gypsum as a soil-softening amendment is not necessary in nonagricultural areas. To keep soil softened, add organic material such as compost or animal manure into the soil each spring before planting time. Apply organic mulch, like hay, around plants and allow it to decompose and work its way down into the soil. The organic material will ensure the soil is softened year round.

How To Soften The Ground For Digging Not only is this difficult if not nearly impossible to dig in, it can create a host of other problems for growing plants in your garden. Ideally, water will absorb through your soil to a depth of about 6 inches. This doesn't happen in hardened soils, water will take the path of least resistance and you'll end up with run off, puddles, and a water depth of only a couple of inches. On ce you have completed the above mix in sand and compost. In the fall put all your leaves on the garden area wet down good and cover with plastic for the winter. If you have as much clay as it sounds u are not going to be very successful until u amend that ground, two inches of lose soil isn't going to allow roots to develop.

Gas-powered augers can make deck footings or fence-post holes fast and easy, but only in some types of soil. In rocky soil, you'll have to stop occasionally to pull out rocks with a clamshell digger. Because of these frustrations, some deck and fence contractors don't bother with power augers and simply hand-dig every hole. Adding sand creates the opposite of the desired effect.

Add organic matter such as compost, peat moss or leaf mold when loosening the soil. If you'd like to quickly break up a hard soil surface for planting, mix the organic matter into the top 3 to 6 inches of soil with a spade. Clay also has moisture retention properties which can be useful during long dry spells.

Earthworms are another way to improve soil compaction. When your soil is compacted, your plants can't grow well. It's something that many gardeners are simply not aware of. Knowing how soil compaction happens and then taking steps towards improving compacted soil will help your garden flourish. A somewhat less quick and easy method is to convert existing clay soil to a non-clay form of soil.

If your growing area is on a slope or hill, the slope may allow water to escape without digging drain paths. Ideally soil has air pockets to allow moisture, worms, roots and microbes to pass through. When soil gets compacted these air pockets get squeezed out and it's harder for plants to grow and for water to reach plants' roots. Water will pool on the surface instead and the plant can literally suffocate.

Cover areas of clay soil with slower composting materials such as bark, sawdust, or ground wood chips. Use these organic materials for mulch, and, as they break down, they will work themselves into the soil below. However, digging post holes can be easier if you manage to get clay soil just below the surface to collect enough water to loosen up. That means you need to be wetting and waiting until the earth below the surface is loose enough to lift.

If the ground does not have enough air space, water and nutrients will not circulate properly, making it difficult for your grass to grow. Luckily there is something you can do to soften and prevent soil hardening. Reseed the affected area, if you're improving a clay soil lawn. If you're amending soil for a vegetable or flower garden, you can begin planting immediately once you've added the amendments. If you don't plan to plant immediately you should cover the area with a heavy layer of mulch to prevent erosion and slow water absorption. Otherwise your hard work might literally be washed away by a heavy rain or two.

Spread 1 pound of gypsum over every 5 square feet of soil. Using gypsum for clay soil will bind the organic matter to the soil particles and prevent the soil from crusting over or cracking once dry. While gypsum adds calcium to the soil, like lime, it doesn't affect your soil's pH as lime does. Till the gypsum into the top 8 inches of soil with the rototiller, then rake the soil surface smooth. Spread a 2-inch deep layer of compost over the soil with a shovel.