Saving data from equation in Marix or Grid then call them later

Question

Ali Kareem 2015-9-25

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/244947-saving-data-from-equation-in-marix-or-grid-then-call-them-later

评论： Star Strider 2015-9-25

采纳的回答： Star Strider

In Mathlab if we have

U=f(Y)+f(Z)

Y have 20 different values

Z have 100 different values

I mean if Y=1 then Z will have 100 different values. For each Y there will be 100 values for Z. this mean I will have 100*20 matrix.

My question is in Mathlab how I can save the output from any equation in any matrix or grid? for this case (100*20)

For example U=Y*Z (when Y=1 then Z have 100 values. Then when Y=3.2 then Z will have 100 new different values)

I mean I need to save the result from any equation in matrix or grid using Mathlab. I need to call these numbers later to use in another function. In addition how I can call each number in this matrix to use it in another equation and how I can drew this numbers ( I mean the number in matrix or grid)

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Star Strider 2015-9-25

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/244947-saving-data-from-equation-in-marix-or-grid-then-call-them-later#answer_193646

编辑：Star Strider 2015-9-25

在 MATLAB Online 中打开

Use the bsxfun function:

f = @(x) sin(x + cos(x));
Y = 0:19;
Z = 1:100;
U = bsxfun(@plus, f(Y), f(Z).');        % Transpose (.') So One Is A Column Vector

Pass ‘U’ to your other function as an argument to it.

6 个评论
显示 4更早的评论隐藏 4更早的评论

Image Analyst 2015-9-25

在 MATLAB Online 中打开

If the 20 values y takes on are 1-20 and the 100 values z takes on are 1-100, and f() is some function you wrote to operate on some single input value, then I think this should work for calculating a 2D matrix "M":

for y=1:20
    for z=1 :100
        M(y, z) = f(y) + f(z);
    end
end

If y and z are some predefined list of weird numbers and the 1-20 and 1-100 are just indexes into those arrays, then you'd do it this way:

for col=1:20
    for row=1 :100
        M(row, col) = f(y(col)) + f(z(row));
    end
end

Not as compact as the way Star showed you though.

Star Strider 2015-9-25

在 MATLAB Online 中打开

OP’s loops will only work if the arguments to the function are also subscripted, the reason I wrote that it would not work as written:

for i=1:20
    for j=1 :100
        M(i,j)=f(y(i))+f(z(j));
    end
end

When timed, bsxfun is much faster than repmat and signficantly faster than a loop.

And then there’s all the bother about using ‘i’ and ‘j’ as variables.

请先登录，再进行评论。

Answer 2

Image Analyst 2015-9-25

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/244947-saving-data-from-equation-in-marix-or-grid-then-call-them-later#answer_193644

You can save them to a .mat file with save() and recall them with load(), or you can pass them via an argument list, or you can use setappdata/getappdata, or make them global, or attach them to handles structure (if you're using GUIDE). See the FAQ:

http://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.28s.29.3F