# Search results

1. ### Auto correlation function for water molecules in a box

I have simulated a box water molecules (1500 water molecules) using molecular dynamics method in NpT ensemble. I got the time auto-correlation function (C(t) vs t, time) where its function line is parallel to x-axis. Which means the C(t) is zero. I understand the water molecules are...
2. ### Velocity auto-correlation

I wish to get some explanation on calculating velocity auto-correlation for water molecules in a box. I have done 100 ns molecular dynamics simulation on 1445 water molecules in a box. Also I have calculated velocity for each water molecule in a frame. A frame contains 1445 water molecules...
3. ### Calculating autocorrelation function

Dear K^2, When I calculate the autocorrelation function for 4000 frames with 1800 (tcorr) as for correlation time. I get negative values after about 600 frame and the graph approach towards tcorr=0. In the literature it is stated as 'caging' effect. What is really means by caging effect...
4. ### Calculating autocorrelation function

Dear K^2, Thanks for your reply. I have few questions to ask relating to equation C(t_j) , to correct my understanding. 1) Does for every new t_j value (called as correlation time), which increases in step wise after each loop, the calculation needed to be done starting from frame 1 until...
5. ### Calculating autocorrelation function

Dear K^2, I calculate angle between lipid and bilayer normal from each frame. So I think there is no random data.
6. ### Calculating autocorrelation function

Thanks sophiecentaur for your reply. Well, can I find the code for this auto-correlation in numerical recipes? Could you suggest any site giving examples?
7. ### Calculating autocorrelation function

Dear Sir/Madam, I am posting this question here because my field of research is biophysics and i am doing molecular dynamics (MD) simulation on bilayer system. Well, what I want is some explanations on calculating auto-correlation function using MD simulation data. I have 4000 frames out...
8. ### Openning new files and write data into them

It compiles. There is no problem. But when I execute it stops says error. The error indicates that the files (maximum_dist_001_064.dat) open ready. That means in the first call of the main-data-file ( UNIT=100) it opens four files. Thay are maximum_dist_001_064.dat maximum_dist_065_128.dat...
9. ### Openning new files and write data into them

Hi, I am trying to write a loop to open four main-data-files. At each open of main-data-file, I want the loop to open another four sub-files and split the data from mail-data-file according to the creteria and dump into the four files. And the process goes on. That means I will have total of...
10. ### Comp Sci Comparing array of data is fortran

The actual section as below:: ! CLASSIFY THE DATA do k=1,noData do l=0, noBins if (ydata(k).ge.ybinPart(l).and.(ydata(k).lt.ybinPart (l+1)))then yBINS(l) = yBINS(l) + 1 end if end do end do
11. ### Comp Sci Comparing array of data is fortran

Dear Sir, Thanks for your explanation. You are correct sir. Actually what I want is the frequency histogram. So in order to get this how the code should be? I need help in this. I appreciate your help in advance. In this process, I have rewritten the code. Below is the code :-...
12. ### Comp Sci Comparing array of data is fortran

Dear sir, I may want to explain like this. Imagine we have x,y and z co-ordinate. Lets say I have 10 values along x-axis and another 10 values along y-axis. The co-ordinates may look like this (x,y). (1,4), (4,6), (2,6), (1,4), (2,6), (8,0), (1,4), (2,6), (1,4), (8,0)...
13. ### Comp Sci Comparing array of data is fortran

Dear Sir, 1) It is true that I can use the same variables for D and BB. But I used them just for my clarity purpose. 2) I used 1 * i since the bin size I used was 1. If the size is 0.5 than I need to replace the 1 with 0.5. This also just for my clarity purpose. 3) Actually what I want is, I...
14. ### Comp Sci Comparing array of data is fortran

Yea I have tried writing the code. It is as below: program array implicit none ! integer, parameter :: D = 60 ! Number of data integer, parameter :: BB=60 ! Number if bins integer i, j, k integer, dimension(1:D) :: xData, yData integer, dimension(1:BB) :: bins integer...
15. ### Comp Sci Comparing array of data is fortran

Hi FORTRAN experts, I have two arrays of data, called data1.dat and data2.dat. each contains 60 data. What I want to do is to compare the data in each file and write the counting into bins. It goes like this. First, take the first data in data1.dat file and compare with the 60 data in...