Chicago Booth Professor: Drew Creal. STATISTICS IN EXCEL - TUTORIAL FOR MAC Tutorial 2. How to Make a Histogram. Now you need to select the data you want a histogram of. To do this click on the red arrow icon by the 11. In the histogram window on StatPlus you will see the field “bin range”. May 11, 2016 - Excel's Histogram tool includes the input data values in bins based on the following logic. Also, you can use the design, layout, and format options of the Chart Tools to change the display of the histogram, for example. On the Format Data Series pane, set the Gap Width to zero. Apps for Excel for Mac. When you create a histogram with statistical software, the software uses the data (including the sample size) to automatically choose the width and location of the histogram bins. The resulting histogram is an attempt to balance statistical considerations, such as estimating the underlying density, and 'human considerations,' such as choosing 'round numbers' for the location and width of bins for histograms. Common 'round' bin widths include 1, 2, 2.5, and 5, as well as these numbers multiplied by a power of 10. The default bin width and locations tend to work well for 95% of the data that I plot, but sometimes I decide to override the default choices. This article describes how to set the width and location of bins in histograms that are created by the UNIVARIATE and SGPLOT procedures in SAS. Why override the default bin locations? The most common reason to override the default bin locations is because the data have special properties. For example, sometimes the data are measured in units for which the common 'round numbers' are not optimal: • For a histogram of time measured in minutes, a bin width of 60 is a better choice than a width of 50. Bin widths of 15 and 30 are also useful. Alarm clock for mac. • For a histogram of time measured in hours, 6, 12, and 24 are good bin widths. • For days, a bin width of 7 is a good choice. • For a histogram of age (or other values that are rounded to integers), the bins should align with integers. You might also want to override the default bin locations when you know that the data come from a bounded distribution. If you are plotting a positive quantity, you might want to force the histogram to use 0 as the leftmost endpoint. If you are plotting percentages, you might want to force the histogram to choose 100 as the rightmost endpoint. To illustrate these situations, let's manufacture some data with special properties. The following DATA step creates two variables. The T variable represents time measured in minutes. The program generates times that are normally distributed with a mean of 120 minutes, then rounds these times to the nearest five-minute mark. The U variable represents a proportion between 0 and 1; it is uniformly distributed and rounded to two decimal places. Word for mac 2011 when i look at on screen page numbers are different from when i print. ![]() Data Hist ( drop=i ); label T = 'Time (minutes)' U = 'Uniform'; call streaminit ( 1 ); do i = 1 to 100; T = rand ( 'Normal', 120, 30 ); /* normal with mean 120 */ T = round (T, 5 ); /* round to nearest five-minute mark */ U = rand ( 'Uniform' ); /* uniform on (0,1) */ U = floor ( 100 *U) / 100; /* round down to nearest 0.01 */ output; end; run; How do we control the location of histogram bins in SAS? Custom bins with PROC UNIVARIATE: An example of a time variable I create histograms with PROC UNIVARIATE when I am interested in also computing descriptive statistics such as means and quantiles, or when I want to fit a parametric distribution to the data. The following statements create the default histogram for the time variable, T. Title 'Time Data (N=100)'; ods select histogram (PERSIST ); /* show ONLY the histogram until further notice */ proc univariate data=Hist; histogram T / odstitle= title odstitle2= 'Default Bins'; run; The default bin width is 20 minutes, which is not horrible, but not as convenient as 15 or 30 minutes. The first bin is centered at 70 minutes; a better choice would be 60 minutes. The HISTOGRAM statement in PROC UNIVARIATE supports two. The ENDPOINTS= option specifies the endpoints of the bins; the MIDPOINTS= option specifies the midpoints of the bins. The following statements use these options to create two customize histograms for which the bin widths are 30 minutes. Proc univariate data=Hist; histogram T / midpoints= ( 60 to 210 by 30 ) odstitle= title odstitle2= 'Midpoints'; run; proc univariate data=Hist; histogram T / endpoints= ( 60 to 210 by 30 ) odstitle= title odstitle2= 'Endpoints'; run; The histogram on the left has bins that are centered at 30-minute intervals. This histogram makes it easy to estimate that about 40 observations are approximately 120 minutes. The counts for other half-hour increments are similarly easy to estimate. In contrast, the histogram on the right has bins whose endpoints are 60, 90, 120. With this histogram, it easy to see that about 35 observations have times that are between 90 and 120 minutes. Similarly, you can estimate the number of observations that are greater than three hours or less than 90 minutes.
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