Recent content by Moly

Hi All. I think i figured it out... i am attaching the program below for a linear set of eqns... that was just to verify that all is working well... however, i was told that the method should converge in one iteration for a linear system, and for me it happens in 3.. am i doing something wrong...

Thanks Gib. I figured where i went wrong.. i still have a question that i will post later today

Now, this is giving me the corrrect answer but not sure if i cheated in a way or not... what do you think: close all clear all x0=0; xt=1; xstep=110; dx=1/(xstep-1); y0=0; yt=1; ystep=110; dy=1/(ystep-1); sum2=0; for i1=1:ystep+1 sum1=0; y=(i1-1)*dy; x2step=floor(y/dx)...

oh... forgot to say that I am using trapazoidal rule for the integration

the program that i put together is giving me the integral=24.8427 and the answer is actually 0.316... my program is copied below, what am i doing wrong: x0=0; xt=1; xstep=11; dx=1/(xstep-1); y0=0; yt=1; ystep=11; dy=1/(ystep-1); sum2=0; for i1=1:xstep sum1=0; y=(i1-1)*dy...

Hi Everyone. I would like to integrate the following using matlab: \int_0^1 ~\int_0^x e^{-x^2} ~dy ~dx looks pretty simple but don't know how to set up the embedded for loops for the integral with in the integral especially that the upper limit of the inner integral is x and not a number...

Hi All. Can somebody give me a sample MATLAB code for Newton-Raphson Method for Nonlinear 4x4 System of Equations. I'm trying to set a very ugly one up and haven't seen NR before the beginning of this week. I've figured the NR for a single eqn but this is driving me nuts.

Hi All. I have an equation that i want to numerically find the root of by using Newton Raphson. However the equation involves an integral which i am using the trapazoidal rule to evaluate. And here is the simplified version of it: 1 = e^{-cy} \int_0^1 e^{-y(1-x)} dx So i am supposed...

Try this: replace every x with the constant a... now the equation should look like it is in one variable, y. So what you need now is to find the second derivative with respect to y. Does that make life easier?

Thanks a lot Borek. I changed Xstep and Nstep from integers to real and now the calculations come out right. I am sure i will have another silly question in a few minutes and your help is muuuuuuuuuuuuuuuuuuuuuuuuuuuuch appreciated

Hi All. I am trying to rewrite a program that i have in MATLAB to one in fortran. as i chug along, i am comparing the results and i am getting funny answers. This is the program in have in fortran so far: ccccccccccccccccccccccccccccccccccccccccccccccccc program main implicit...

thanks

Thank you for your reply. i tried the first few before posting my question and could not really figure it out. any advice as to which specific option to use?

Thanks for the prompt reply Borek. I am glad I asked instead of banging my head against the screen until next week. Thanks again.

Hi All Matlab is displaying numbers with 4 decimal places and i hate when it does that for whole numbers. for example i have a matrix C(i) that starts off from 1 down to 150/275. When i multiply it by 275 i get the first entry as 275.0000 and the last as 150.0000 how do i turn that off or...