Free42 with Matrix Exponential

12242021, 01:21 PM
Post: #1




Free42 with Matrix Exponential
Hi,
Free42 seems to accept square matrix for the e^x function, but returns wrong results. For example, make a matrix [2x2 matrix] with {{0,0},{0,0}} and press e^x. The correct result must be {{1,0},{0,1}}, Free42 returns {{1,1},{1,1}}. Next example, input {{0, pi},{pi,0}} and e^x. The correct result is {{1,0},{0,1}}, Free42 gets {{1,e^pi},{e^pi,1}}. Next example, input [3x3 matrix] with {{0,0,0},{0,0,0},{0,0,0}} and e^x. The correct result is {{1,0,0},{0,1,0},{0,0,1}}, Free42 returns {{1,1,1},{1,1,1},{1,1,1}}. Is this a bug? or am I operating it in a wrong way? I am using Free42 3.0.8 and DM42 (DMCP 3.22, DM42 3.20, Free42 3.0.5). Akira 

12242021, 02:26 PM
Post: #2




RE: Free42 with Matrix Exponential
Like the HP42S, Free42 applies unary functions to matrices elementwise, so the results you cite are as expected. If a true matrix exponential is desired, it would have to be implemented in user code, or added as a new, separate function.


12242021, 11:56 PM
Post: #3




RE: Free42 with Matrix Exponential
I see. I was so naive. Thanks for your trouble.
Akira (12242021 02:26 PM)Thomas Okken Wrote: Like the HP42S, Free42 applies unary functions to matrices elementwise, so the results you cite are as expected. If a true matrix exponential is desired, it would have to be implemented in user code, or added as a new, separate function. 

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