HP 48gII hp 48gII_user's manual_English_E_HDPMSG48E67_V2.pdf - Page 673

This can be used to execute at once any sub-program called from within a main program. Examples of the application of @@SST@ will be shown later. Fixing the program The only possible explanation for the failure of the program to produce a numerical result seems to be the lack of the command NUM after the algebraic expression '2*a^2+3'. Let's edit the program by adding the missing EVAL function. The program, after editing, should read as follows: « "Enter a: " {" :a: " {2 0} V } INPUT OBJ→ → a « '2*a^2+3' NUM » » Store it again in variable FUNCa, and run the program again with a = 2. This time, the result is 11, i.e., 2*22+3 = 11. Input string for two or three input values In this section we will create a sub-directory, within the directory HOME, to hold examples of input strings for one, two, and three input data values. These will be generic input strings that can be incorporated in any future program, taking care of changing the variable names according to the needs of each program. Let's get started by creating a sub-directory called PTRICKS (Programming TRICKS) to hold programming tidbits that we can later borrow from to use in more complex programming exercises. To create the sub-directory, first make sure that you move to the HOME directory. Within the HOME directory, use the following keystrokes to create the sub-directory PTRICKS: ³~~ptricks` „°@)@MEM@@ @)@DIR@@ @CRDIR J Enter directory name 'PTRICKS' Create directory Recover variable listing A program may have more than 3 input data values. When using input strings we want to limit the number of input data values to 5 at a time for the simple reason that, in general, we have visible only 7 stack levels. If we use Page 21-24