I want to write matlab code for the following problem : I have suppose two dataset for a given time period. Now I want to know for a given time interval how many times the dataset variables have equal values and I want to plot a surface between them

I have two Dataset of n×1 size for given time period. Now I want to create a function which will plot the surface graph between dataset01 and dataset02 and how many time both the dataset have common value between them. The function can ask me number of intervals and it should give me output a surface plot.

[Bob Thompson]

What do you have so far for your code?

[Kuldeep Parmar]

function t = jpd1(x,y,n)
%x=dataset 01
%y=dataset 02
%n=number of intervals

h=length(x)/n;
count=zeros(1,length(x));
%for loop to find the number of same values in given ineterval in database
for i=1:h:length(x)
    for j=i:1:h
        k=1;
        if x(j) == y(j)
            count(i)=0+k;
        else
            count(i)=0;
        end
    end
end
count

plot(x,y,count)

[Bob Thompson]

'find the number of same values in given ineterval '

What exactly does this mean? Are you just looking for how many duplicates there are total, or for specific values? Any time I want to know the number of unique values, or number of duplicates I usually start looking into using unique.

Aside from that, what problems are you having? You have outlined what you are trying to do, but haven't said anything about why it isn't working? What results are you seeing, and how do they differ from what you would expect. Are you getting error messages? If so, post the entire error message.

[Kuldeep Parmar]

I want to know if there are same values between given interval in two dataset then how many times are there, I am not concered about the what value is that but how many times it it common between them. And I am getting following error messages :

Error using plot

Data must be a single matrix Y or a list of pairs X,Y.

[Guillaume]

It's still really not clear what it is you're trying to do. And the completely non-working code that you posted doesn't clarify.

It seems that your code tries to compare values of x and y at the same index. So why bother with intervals?

Problems with the code you've posted:

h=length(x)/n;

So, most likely h is not integer

for i=1:h:length(x)

So, i will be 1 at the first step, h+1 at the second step, 2*h+1 at the 3rd step, etc. Apart from the first step, it's very unlikely that i will be integer, yet:

    count(i) = ...

you use i as an index. Non-integer indices are not valid. Note that since j starts at i, j will also be non-integer after the 1st step, so x(j) and y(j) are also non-valid.

Also, as stated, on the first step i will be 1, so

for j=i:1:h

will be fine, it's just

for j = 1:h 

On the second step, i is h+1, so the j loop is then

for j = h+1:h

Since the start is greater than the end, the loop won't even start. It will be the same for every iteration. The j loop is only executed when i is 1.

Then we have

    count(i) = 0+k;

0+k is of course just k and since k is always 1, The above is simply

    count(i) = 1;

[Kuldeep Parmar]

Sorry for the poor explanation of the problem. Let me elabroste it:

Let us say in the pipe flow at a given point I am measuring fluid flow velocity and aceleration at every 1 sec interval. So now I have two dataset of velocity and accelaration at every 1 sec interval. Now I want to write a code which will give me in the given interval, let us say 10 sec will tell me how many times velocity and accelaration have assumed same values and plot the graph between velocity,accelaration and number of times they have assumed same values in the given interval.