Generating a matrix based on an equation with conditions

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A Aln
A Aln 2019-3-22
评论： A Aln 2019-3-22
Hello,
Are there any way to do the following?
I want to generate a n*1 matrix based on this equation:
M = T1*G*Z1 - T2*G*Z2 + F - C*P
all variables are known and constant but with the following conditions:
1) F is zero in the entire column, excpet at a certain row, its equal to a constant number
2) From Row 1 to a certain row, this term (T2*G*Z2) is zero, for example until row 200. While from row 201 to the end, the previous term has constant value but this term (T1*G*Z1) is zero.
Thanks
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Guillaume
Guillaume 2019-3-22
If is most likely not needed.
What are the size of all the variables (T1, G, etc.)?
If they are not scalar variables did you mean * or .* for the multiplications?
A Aln
A Aln 2019-3-22
编辑：A Aln 2019-3-22
Yes I mean Multiplication, My problem is to make the conditions
if row 50 onward, change the value from 1 to 2
I can change single value by using this for example
A(5,1)=5;
But how can I change any number below this row

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Matt J
Matt J 2019-3-22
For example,
>> A=zeros(10,1); A(1:5)=4; A(6:10)=3
A =
4
4
4
4
4
3
3
3
3
3
  1 个评论
A Aln
A Aln 2019-3-22
thank you so much, that what I did before, somehow horrible
r1 = (dH*grav*delz) - (accm*pi);
r2 = -(dB*grav*delz) - (accm*pi); %% The eqn
RR = zeros(x*y*z,1);
RR(1:x*y,1:1)=r1;
RR((x*y)+1:x*y*z,1:1)=r2;
RR(well,1)=RR(well,1)+q;
the variables are different and not defined here bcs its part of big code, Again I really appreciate your help

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