generated "unvaforable zero" value from multiplying two matrices, how to solve/correct it?

3 次查看（过去 30 天）

M Adli Hawariyan 2022-7-21

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1764830-generated-unvaforable-zero-value-from-multiplying-two-matrices-how-to-solve-correct-it

编辑： M Adli Hawariyan 2022-7-21

for simplicity, i have a two matrices A and B generated by matlab like below. when i calculated manually by excel with the function mmult(A;B) the value of C is vaforable like this. even when i increasing the decimal. especially the value of cell matrix C at 3,1 it was definetly zero

but when i multiply them in matlab i got value of C like this

how to deal with this type of problem? any guidance will help me alot, because i got bunch of wild value zero like this :( thanks a lott.

the following attachments is my full code, matrix A is k_sup and matrix B is uaa, and matrix C is Fsupt in my line code. input3Dxlsx is my input.

P.S

i tried calculate separately with new script (like the following A*B bottom), copy those matrices from generated excel (so the value is accurate), and the generated value of matrix C is entirely different, like this:

here is the following matrix A and B i copy from generated excel

A = [-3710000000	0	0	0	0	0;
    0	-12624305.56	0	0	0	75745833.33;
    0	0	-2318750	0	-13912500	0;
    0	0	0	-69358333.33	0	0;
    0	0	13912500	0	55650000	0;
    0	-75745833.33	0	0	0	302983333.3]
A = 6×6
1.0e+09 *

   -3.7100         0         0         0         0         0
         0   -0.0126         0         0         0    0.0757
         0         0   -0.0023         0   -0.0139         0
         0         0         0   -0.0694         0         0
         0         0    0.0139         0    0.0556         0
         0   -0.0757         0         0         0    0.3030
B = [0
    0
    -0.025876011
    0
    0.004312668
    0]
B = 6×1
         0
         0
   -0.0259
         0
    0.0043
         0
C = A*B
C = 6×1
1.0e+05 *

         0
         0
    0.0000
         0
   -1.2000
         0