How to combine multiple numbers into 1 number?

Question

Hieu 2023-2-25

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评论： Steven Lord 2023-2-25

I have the numbers R1, R2, Zr1, that I want to fuse together into 24000 . Zr1 is an array, while R1 and R2 are double. I have tried strcat but it only produces 240 0 0 which is not the intended 24000

R1 = 2

R2 = 4

Zr1 = 0 0 0

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Stephen23 2023-2-25

"Zr1 is an array, while R1 and R2 are double"

All doubles are arrays. Scalars are not a separate type, because in MATLAB everything is an array:

https://www.mathworks.com/help/matlab/matlab_prog/fundamental-matlab-classes.html

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Answer 1

Stephen23 2023-2-25

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https://ww2.mathworks.cn/matlabcentral/answers/1918685-how-to-combine-multiple-numbers-into-1-number#answer_1179675

编辑：Stephen23 2023-2-25

在 MATLAB Online 中打开

General solution:

R1 = 2;
R2 = 4;
Zr1 = [0,0,0];
V = [R1,R2,Zr1];
N = 10.^(numel(V)-1:-1:0) * V(:)
N = 24000

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Stephen23 2023-2-25

在 MATLAB Online 中打开

"can you explain how N = 10.^(numel(V)-1:-1:0) * V(:) works?"

Break code down to know how it works. You can do this yourself.

R1 = 2;
R2 = 4;
Zr1 = [0,0,0];
V = [R1,R2,Zr1] % so V is a 1x5 vector: [10000's,1000's,100's,10's,1's]
V = 1×5
     2     4     0     0     0

Clearly all we need to do is to multiply the elements of V by the corresponding power of ten, and then add them together. Note that [10000,1000,100,10,1] is just [1e4,1e3,1e2,1e1,1e0] which is just 10.^[4,3,2,1,0]. So that is very easy to generate:

P = numel(V)-1:-1:0
P = 1×5
     4     3     2     1     0
Q = 10.^P
Q = 1×5
       10000        1000         100          10           1

Then one simple matrix multiplication does both the multiplying and the addition:

Q * V(:)
ans = 24000

https://en.wikipedia.org/wiki/Matrix_multiplication

Steven Lord 2023-2-25

在 MATLAB Online 中打开

Another way to generate the Q vector is with logspace.

Q = logspace(4, 0, 5)
Q = 1×5
       10000        1000         100          10           1

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Answer 2

Alan Stevens 2023-2-25

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https://ww2.mathworks.cn/matlabcentral/answers/1918685-how-to-combine-multiple-numbers-into-1-number#answer_1179670

编辑：Alan Stevens 2023-2-25

在 MATLAB Online 中打开

Do you mean

R1 = 2; R2 = 4; Zr1 = [0 0 0];
R = R1*10^4+R2*10^3+Zr1(1)*10^2+Zr1(2)*10+Zr1(3)
R = 24000

Alternatively:

R1 = 2; R2 = 4; Zr1 = [0 0 0];
R = [R1, R2, Zr1]
R = 1×5
     2     4     0     0     0
M = 10.^[4 3 2 1 0]
M = 1×5
       10000        1000         100          10           1
R = M*R'
R = 24000