# The UNIVARIATE Procedure

### Example 4.14 Creating a Histogram

This example illustrates how to create a histogram. A semiconductor manufacturer produces printed circuit boards that are sampled to determine the thickness of their copper plating. The following statements create a data set named `Trans`, which contains the plating thicknesses (`Thick`) of 100 boards:

```data Trans;
input Thick @@;
label Thick = 'Plating Thickness (mils)';
datalines;
3.468 3.428 3.509 3.516 3.461 3.492 3.478 3.556 3.482 3.512
3.490 3.467 3.498 3.519 3.504 3.469 3.497 3.495 3.518 3.523
3.458 3.478 3.443 3.500 3.449 3.525 3.461 3.489 3.514 3.470
3.561 3.506 3.444 3.479 3.524 3.531 3.501 3.495 3.443 3.458
3.481 3.497 3.461 3.513 3.528 3.496 3.533 3.450 3.516 3.476
3.512 3.550 3.441 3.541 3.569 3.531 3.468 3.564 3.522 3.520
3.505 3.523 3.475 3.470 3.457 3.536 3.528 3.477 3.536 3.491
3.510 3.461 3.431 3.502 3.491 3.506 3.439 3.513 3.496 3.539
3.469 3.481 3.515 3.535 3.460 3.575 3.488 3.515 3.484 3.482
3.517 3.483 3.467 3.467 3.502 3.471 3.516 3.474 3.500 3.466
;
```

The following statements create the histogram shown in Output 4.14.1.

```title 'Analysis of Plating Thickness';
ods graphics on;
proc univariate data=Trans noprint;
histogram Thick / odstitle = title;
run;
```
```title 'Enhancing a Histogram';
proc univariate data=Trans noprint;
histogram Thick / midpoints    = 3.4375 to 3.5875 by .025
rtinclude
outhistogram = OutMdpts
odstitle     = title;
run;

proc print data=OutMdpts;
run;
```

The NOPRINT option in the PROC UNIVARIATE statement suppresses tables of summary statistics for the variable `Thick` that would be displayed by default. A histogram is created for each variable listed in the HISTOGRAM statement.

Output 4.14.1: Histogram for Plating Thickness

A sample program for this example, uniex08.sas, is available in the SAS Sample Library for Base SAS software.