HP Prime CAS programming

[ramon_ea1gth]

I have been very interested in understanding how to call CAS functions from HOME (thinking about including these calls in a HOME program or a custom app). So I found this post extremely interesting, although the original hints have some years. Thus, I have done some tests with firmware version 2.1.14433 (2020 01 21), using variables of string type and in the end the options that work for me are summarised in this small program:

Code:

EXPORT TEST()
BEGIN
LOCAL RES1, RES2, CMD1:="diff(3*x^2+5*x)";

RES1:=CAS.diff("3*x^2+5*x");
RES2:=CAS(EVAL(CMD1));
RETURN RES2;
END;

This program calls the diff() CAS command to differenciate an expression. It works both in CAS as in HOME screens. The result in HOME screen is '3*2*x+5'; in CAS screen, the output is '6*x+5' (it is simplified). It is possible to edit the RETURN line to RETURN RES1, obtaining the same outcome. Notice the application of the EVAL command.