## Squareing Matrix(?) in MATLAB

Hello, I've got quick questions.
1. When I have a matrix, x, and try to get different values for each x (given y = (x^2)+b),
I get this error.

??? Error using ==> mpower
Matrix must be square.

2. x is [1x101] double according to MATLAB and I've had this problem when I was taking derivative as well. I've lost numbers throughout the derivative, which i understands.
so x' = [1x100] and x'' = [1x99] and so forth.

What's the best way to solve these problems.
Thank you.

 Quote by krnhseya Hello, I've got quick questions. 1. When I have a matrix, x, and try to get different values for each x (given y = (x^2)+b), I get this error. ??? Error using ==> mpower Matrix must be square. 2. x is [1x101] double according to MATLAB and I've had this problem when I was taking derivative as well. I've lost numbers throughout the derivative, which i understands. so x' = [1x100] and x'' = [1x99] and so forth. What's the best way to solve these problems. Thank you.
 >> x=sqrt(500/105); >> a=[0:0.1:100]; >> b=[0:1:100]; >> z=a/(2*(sqrt(3000*15))); >> p=x(sqrt(1-((z)^2))) ??? Error using ==> mpower Matrix must be square. this is not the direct problem but it's basically the same thing. Why am I getting this error? I will hold onto my second question for now.  another question... >> x=A*(exp(-(z*wn*t)))*(sin(wd*t)) ??? Error using ==> mtimes Inner matrix dimensions must agree. everything is numeric except t is in matrix...

## Squareing Matrix(?) in MATLAB

 Quote by krnhseya >> x=sqrt(500/105); >> a=[0:0.1:100]; >> b=[0:1:100]; >> z=a/(2*(sqrt(3000*15))); >> p=x(sqrt(1-((z)^2))) ??? Error using ==> mpower Matrix must be square. this is not the direct problem but it's basically the same thing. Why am I getting this error?
It looks like you are using the matrix power operator ^ where you should be using the array power operator .^ . The matrix power operator A^n multiplies the matrix A by itself n times, which means the number of columns in A must be equal to the number of rows in A, which means that A must be square (size(A) = [m x m] for some positive integer m). The array power operator A.^n raises each element of A to the nth power, and therefore has no restrictions on the dimensions of A.

 another question... >> x=A*(exp(-(z*wn*t)))*(sin(wd*t)) ??? Error using ==> mtimes Inner matrix dimensions must agree. everything is numeric except t is in matrix...
Once again, it looks like you are using a matrix operator where you should be using an array operator. Try (exp(-z*wn*t))) .* (sin(wd*t))
 thanks a lot! i've got another question...sorry. i am given that function and there are two independent variables, t and a, which i posted above. i am told that it's initial displacement is zero but it "dies out" after about t=2. so basically, after x has been graphed up to t<2 and when t hits 2 seconds mark, i think everything converges to zero i believe. i tried everything without using mfile but i couldnt figure out so i thought i should use mfile instead so i've retyped everything under... t=[0:0.1:10]; b=[0:1:100]; if 0=
 Hi I'm trying to integrate a function func1 in Matlab but I keep getting errors I realy don't know what I'm doing wrong. Can anyone tell me? Here is the code Im using: function [ f1 ] = func1( E, Delta, kB, Temp ) %func1: calculates integrand for eqn 1 % Detailed explanation goes here f1=(tanh(sqrt(((E*E)+(Delta*Delta))))/(2*kB*Temp))/(2*(sqrt(((E*E)+(Delta*Delta))))); end Command line code: >> hbar=1.054E-34; Tdebye=420; h=6.626E-34; kB1= 1.38065E-23; >>fdebye=(Tdebye*kB1)/h; >> Temp1=0.5; >> Delta1=0; >> a=hbar*fdebye; >> Q=quad(@(E1)func1(E1,0,1.38065E-23,0.5),-a,a) ??? Error using ==> mtimes Inner matrix dimensions must agree. Error in ==> func1 at 4 f1=(tanh(sqrt(((E*E)+(Delta*Delta))))/(2*kB*Temp))/(2*(sqrt(((E*E)+(Delta*Delta))))); Error in ==> @(E1)func1(E1,0,1.38065E-23,0.5) Error in ==> quad at 77 y = f(x, varargin{:});