newRPL - build 1255 released! [updated to 1299]
06-03-2019, 01:12 PM
Post: #470
 JoJo1973 Member Posts: 111 Joined: Apr 2016
RE: newRPL - build 1255 released! [official and unofficial]
(06-03-2019 12:13 PM)Claudio L. Wrote:
(06-03-2019 09:32 AM)Nigel (UK) Wrote:  Two points:
• Entering '(0,1)' onto the stack and then pressing EVAL returns the list { '0' '1' } rather than the complex number (0,1). This may or may not be by design, but it surprised me.
• Entering 'sqrt(-2)' onto the stack and then pressing EVAL crashes both the physical calculator and the PC emulator.
Both of these operations are carried out with the complex results flag checked.

I haven't used newRPL for a while and it is wonderful to see how much progress has been made. George R R Martin could learn a thing or two from Claudio!

Nigel (UK)

I updated the unofficial ROMs with a few bugfixes, I believe the crash you mentioned above should be resolved.
Also, complex numbers can't be expressed with parenthesis in a symbolic. You basically called a function without any name or command, therefore the list of arguments was returned as it was on the stack. This is part of the not-so-new support for multivalued functions in a symbolic. You can return multiple results and will be packed into a list.

Edit: Just for completeness, to express a symbolic you need to use a+b*i where the complex i is not the letter 'i' but the one on Alpha-LS-7.

This prompted me to test if it's possible to express complex numbers in polar form into symbolics: I found two issues.

1) (-1+i) = (sqrt(2),∡135º) so at first I tried to build 'sqrt(2)*e^(i*∡135º)' by steps: I failed because symbolic i units can't be multiplied by an angle using the '*' key. Nevertheless, typing the whole expression on the command line was accepted by the parser.

2) Evaluation gave a wrong result because I was in DEG mode and ∡135º was converted to 135 rather than 3*pi/4. Repeating the test in RAD mode returned the correct result.

IMHO multiplication of complex by angle should be allowed and considered a special case whereas the angle is always converted to a real in radians regardless current angular mode: it's the only case where there should be a deviation from the standard treatment which, in other situations, it's useful and straightforward.
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