My first PHP program: Odds ratio and Cox index calculator

Finally ... at the age of 50 (!) ...  I was able to write my first PHP program.

http://www.estat.us/file/calc.php

 

Based on the results of logistic regression model (the intercept and the program impact estimate -- all expressed in logit), this program allows a user to calculate an odds ratio statistic and a standardized effect size (Cox index).  The algorithm can be found in What Works Clearinghouse's standard document:

WWC procedures handbook (see page. 14)
WWC standards slides (Definition of small sample size correction, slide 14)

I replied on the following materials:

Udemy, Reece Kenny's Create a REAL Social Network like Facebook in PHP + MySQL.  Honestly I didn't complete this course, but I learned how to run PHP and MySQL on my PC by installing XAMPP and running files from the XAMPP's subfolder (C:\xampp\htdocs).  I also would have never figured out how to look at results by opening the file from localhost (e.g., http://localhost/calc.php).

Michiko's code.  I first copied her simple calculator example and modified it to make my program.

 

Not seeing a MySQL table I just created

I created a new blank MySQL database.  I couldn't see it when accessing it via. phpMyAdmin.   I only saw two old MySQL databases.

It turns out that the new one was associated with a different user name.   I had to log out of the screen first by clicking on one of the icons on the left-upper side of the phpMyAdmin window.   After the log-out, I logged in with the right user name and the password, when I was able to see all MySQL databases I needed to see.

Each phpMyAdmin session is specific to each of the users I created.

PHP if statement

if ($money > $taxIncludedPrice) {
echo 'You can buy this item';
} elseif ($money == $taxIncludedPrice) {
echo 'You can buy this item, but you will not have any money left';
} else {
echo 'You cannot buy this item';
}