topic Re: equation solve in PTC Mathcad
https://community.ptc.com/t5/PTC-Mathcad/equation-solve/m-p/631694#M187639
<P>You should have said in the other thread that you just want it to be solved using specific values and not symbolically.</P>
<P>With c=0.5 you end up with a cubic equation and the symbolic solve is able to provide all three solutions for each value of sigma.s</P>
<P> </P>
<P>But the expression in parenthesis is a scalar and this can't equal a vector sigma.s</P>
<P> </P>
<P>You may turn the symbolic calculation into a function of sigma.s and later call that function vectorized to get the 5 x 3 solutions. Note that the solutions with 10^-16 or so as imaginary part are supposed to be real values.</P>
<P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="clipboard_image_1.png" style="width: 400px;"><img src="https://community.ptc.com/t5/image/serverpage/image-id/20208iD5EDDB597192E765/image-size/medium?v=v2&px=400" role="button" title="clipboard_image_1.png" alt="clipboard_image_1.png" /></span></P>
<P> </P>
<P>If you are just looking for one real solution, you may consider using the numeric "root" function (you may also use a solve block instead):</P>
<P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="clipboard_image_2.png" style="width: 400px;"><img src="https://community.ptc.com/t5/image/serverpage/image-id/20210i9F1268AD10F81E35/image-size/medium?v=v2&px=400" role="button" title="clipboard_image_2.png" alt="clipboard_image_2.png" /></span></P>
<P>In case you are interested in the negative values for EC only, you may use a solve block with an appropriate constraint or the root function in its second flavor:</P>
<P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="clipboard_image_3.png" style="width: 400px;"><img src="https://community.ptc.com/t5/image/serverpage/image-id/20211i290A35CA582474B8/image-size/medium?v=v2&px=400" role="button" title="clipboard_image_3.png" alt="clipboard_image_3.png" /></span></P>
<P> </P>
<P>Worksheet in format Prime 6 attached.</P>
<P>Not, that if you use Prime 6 the symbolic solution will only work if you set the calculation to "Legacy symbolic" which activates muPad. The new FriCAS is not able to solve this cubic equation.</P>
<P> </P>Wed, 16 Oct 2019 16:03:38 GMTWerner_E2019-10-16T16:03:38Zequation solve
https://community.ptc.com/t5/PTC-Mathcad/equation-solve/m-p/631682#M187636
<P>Hello,</P>
<P> </P>
<P>I am using the solve command to solve for EC for a given matrix of sigma.s, It is unable to find a solution. Please suggest.</P>
<P> </P>
<P>Thanks,</P>
<P> </P>
<P>Faisal</P>Wed, 16 Oct 2019 15:24:25 GMThttps://community.ptc.com/t5/PTC-Mathcad/equation-solve/m-p/631682#M187636fahmed-22019-10-16T15:24:25ZRe: equation solve
https://community.ptc.com/t5/PTC-Mathcad/equation-solve/m-p/631694#M187639
<P>You should have said in the other thread that you just want it to be solved using specific values and not symbolically.</P>
<P>With c=0.5 you end up with a cubic equation and the symbolic solve is able to provide all three solutions for each value of sigma.s</P>
<P> </P>
<P>But the expression in parenthesis is a scalar and this can't equal a vector sigma.s</P>
<P> </P>
<P>You may turn the symbolic calculation into a function of sigma.s and later call that function vectorized to get the 5 x 3 solutions. Note that the solutions with 10^-16 or so as imaginary part are supposed to be real values.</P>
<P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="clipboard_image_1.png" style="width: 400px;"><img src="https://community.ptc.com/t5/image/serverpage/image-id/20208iD5EDDB597192E765/image-size/medium?v=v2&px=400" role="button" title="clipboard_image_1.png" alt="clipboard_image_1.png" /></span></P>
<P> </P>
<P>If you are just looking for one real solution, you may consider using the numeric "root" function (you may also use a solve block instead):</P>
<P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="clipboard_image_2.png" style="width: 400px;"><img src="https://community.ptc.com/t5/image/serverpage/image-id/20210i9F1268AD10F81E35/image-size/medium?v=v2&px=400" role="button" title="clipboard_image_2.png" alt="clipboard_image_2.png" /></span></P>
<P>In case you are interested in the negative values for EC only, you may use a solve block with an appropriate constraint or the root function in its second flavor:</P>
<P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="clipboard_image_3.png" style="width: 400px;"><img src="https://community.ptc.com/t5/image/serverpage/image-id/20211i290A35CA582474B8/image-size/medium?v=v2&px=400" role="button" title="clipboard_image_3.png" alt="clipboard_image_3.png" /></span></P>
<P> </P>
<P>Worksheet in format Prime 6 attached.</P>
<P>Not, that if you use Prime 6 the symbolic solution will only work if you set the calculation to "Legacy symbolic" which activates muPad. The new FriCAS is not able to solve this cubic equation.</P>
<P> </P>Wed, 16 Oct 2019 16:03:38 GMThttps://community.ptc.com/t5/PTC-Mathcad/equation-solve/m-p/631694#M187639Werner_E2019-10-16T16:03:38ZRe: equation solve
https://community.ptc.com/t5/PTC-Mathcad/equation-solve/m-p/631702#M187641
<P>Thank you very much and sorry for the early mistake. It helped me and I will work with it more to see with other changes.</P>
<P> </P>
<P>Faisal</P>Wed, 16 Oct 2019 16:28:07 GMThttps://community.ptc.com/t5/PTC-Mathcad/equation-solve/m-p/631702#M187641fahmed-22019-10-16T16:28:07Z