Recent content by kelvin490

Hi, everyone. I would like to test for the reaction between carbonic acid and copper (to simulate the effect of acid rain on copper). However, I find that many supplies failed to provide carbonic acid (either in powder or liquid form). Some says that carbonic acid is unstable and thus cannot...

I would like to solve an equation below using MATLAB: All the parameters except p are known, so I only need to solve for p. However since I need to consider the sign of the integrand and there is an absolute value sign in it I don't know how to solve it. Could anyone please help? Thank you.

I want to represent data with 2 variables in 2D format. The value is represented by color and the 2 variables as the 2 axis. I am using the contourf function to plot my data: load('data.mat') cMap=jet(256); F2=figure(1); [c,h]=contourf(xrow,ycol,BDmatrix); set(h, 'edgecolor','none'); Both xrow...

I have changed to use scatter instead of plot, as suggested by other So the command becomes: scatter(x_dis,y_dis,[],dis_color(1:nDis,:),'.') It works like a charm

I want to make a 2D plot of points with different x, y coordinates and have colors depending on a separate variable. I have make column vectors for x and y coordinates and another column containing 1 or -1. I would like to represent the points with 1 as red and -1 as blue points. I have codes as...

Is there any method to extract data from a graph in JPEG/TIFF format, using simple software such as MATLAB? I have a graph as shown below: I only have this picture but no raw data and I want to plot the black curve in this graph. How to get approximate numerical data of the x and y axis...

Finally I solve it in the following way: if (step==1) xlswrite(filename,array,sheetname,'A1'); %Create the file else [~,~,Data]=xlsread(filename,sheetname); %read in all the old data OriCol=size(Data,2); %get the column number of the old data NewCol=OriCol+1; %the new array...

I would like to ask how to use MATLAB to append new columns into existing excel file without altering the original data in the file? In my case I don't know the original number of columns and rows in the file and it is inefficient to open the files one by one and check in practice. Another...

Thanks. It's seems there is a theorem that a vector space Q that the dimension is n can have any set of n linearly independent vectors k1,k2...kn as its basis. How can we ensure that k1,k2...kn doesn't form a vector space other than Q but not Q? I have this question because two different set of...

If we use n linearly independent vectors x1,x2...xn to form a vector space V and use another set of n linearly independent vectors y1,y2...yn to form a vector space S, is it necessary that V and S are the same? Why? If we have a vector space Q that the dimension is n, can we say that any set of...

I used a function called ind2patch to make a big 3D block which contains a number of smaller blocks in 3 dimensions. Each small block has a value which the magnitude is represented by a color.One example is shown below: However, most of the boxes have very low or zero value and I don't need to...

Yes, it's a Linux cluster and my OS is Win 8. In the cluster I use commands like pgf90 to compile the program and in my PC I use GNU or PGI Fortran. Are there any means to convert the files back to desirable format?

I can attach it now. Thanks a lot.

Sorry for the trouble. Actually I tried to attach pictures directly but it still ask me to put the picture's URL. I copied the link to it but it seems doesn't work. For the .dat file, I only know it's .DAT type by checking the properties of the file. In Fortran I just use the "open" function...

I have generated some .dat files using Fortran on a cluster. I need to use WinSCP(https://winscp.net/eng/download.php) to access files in the cluster so sometimes I just use the WinSCP to open the .dat files generated. The data can be shown regularly like this one...