When testing SUM where I simply have the program label and return as my program, when I enter 1 enter 100, and then press SUM, then program name, then enter, I get my expected 5050. I was expecting ~1.711E98 when pressing 1 enter 69 PROD program name, enter. Instead, I get zero. What am I doing wrong?

Instead of providing the range in X and Y you need to provide in X a loop control number in the format cccccc.fffii : at each run cccccc is decremented by ii until cccccc is less than fff. If ii=0 cccccc is decremented by 1.

In your example for SUM you have 100 in X : cccccc=100, fff=0 and ii=0, so SUM is doing the sum of your function from 100 to 0. Adding 0 at the end doesn’t change the sum, but for PROD, multiplying by 0 at the end returns 0.

You should use 69.001 as the starting value in X for PROD.

Another question…is matrix entry and operation easier on the WP 34S platform on the DM 42? I believe that programs are in the library…I do not know how to operate any of these capabilities…

Not sure how it works on the DM 42 but if it is anything similar to the original WP-34S the following might help:

You didn't ask for complex matrix operations but it still might give you an idea.

As far as I remember it's doable but not really fun.

Thus it is probably much easier on a DM 42.

(02-28-2022 04:47 PM)lrdheat Wrote: [ -> ]Another question…is matrix entry and operation easier on the WP 34S platform on the DM 42? I believe that programs are in the library…I do not know how to operate any of these capabilities…

If you mean easier on the WP34S THAN on the DM42, then absolutely not. Matrix operations are very poorly implemented and difficult to use on the WP34S, and it requires careful memory management. There is no native matrix data type, and all operations require calls to functions. There is no editor for easy matrix data entry either. As far as hardware is concerned, the underlying HP 30b hardware is crippled by limited memory, so only small matrices are possible. Finally, the DM 42 has an internal flash drive for saving programs and well as a USB port for saving programs to a computer and reflashing the firmware, If you want to use matrices on something other than the DM42, you might want to try the new WP43S emulator, which is still under development.

Just to be clear: the WP34S implementation on the DM42 hardware has exactly the same matrix capabilities as the original WP34S. I didn't add anything in this area.

To be specific, I compiled the code with MATRIX_ROWOPS and MATRIX_LU_DECOMP enabled, and SILLY_MATRIX_SUPPORT disabled.

Here's a link to the WP34S code on Sourceforge. There's a helpful file

matrix.txt in the

doc/ folder which goes through the available matrix commands on the WP34S. In the

library/ folder there's source code for a program called MED in the file

matrixedit.wp34s, which makes entering and viewing matrices less hard than it might otherwise be. The file contains documentation for the program. It can be compiled and loaded in the usual way.

If it is necessary to work with matrices on the DM42 hardware, the Free42 implementation is easier to use than the WP34S.

Hope this helps!

Nigel (UK)