Using vpasolve to solve equation for all values in matrix

16 views (last 30 days)
Is it possible to use vpasolve to solve a particular equation for all values in a matrix without looping? i have a large number of matrices and looping through them all will be very slow.
% Minimal working example
h=rand(5,5);
h_long=reshape(h,[size(h,1)*size(h,2),1]);
store_arr=zeros(numel(h_long),1);
for a=1:numel(h_long)
curr_pix=h_long(a);
tt=vpasolve(5*((1-exp(-5/x)*sind(14))/((1-exp(-5/x))*cosd(14)))==curr_pix, x);
store_arr(a)=tt;
end
fin_mat=reshape(squeeze(store_arr),size(h))
This is a miniature version of what i am doing. my matrix has 4 dimensions and are quite large.
Thanks,
Maria

Accepted Answer

Walter Roberson
Walter Roberson on 4 Jun 2018
No, vpasolve() will always consider matrix inputs as being equations to be solved simultaneously.
If you switch to symbolic curr_pix then you can solve() the equation, getting
ttsol = -5./ln(-(-5+curr_pix*cosd(14))./(-curr_pix*cosd(14)+5*sind(14)))
after which you can fin_mat = subs(ttsol, curr_pix, h) to get a matrix of solutions that skips the reshapes()
  3 Comments

Sign in to comment.

More Answers (0)

Categories

Find more on Symbolic Math Toolbox in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!