How to get mesh to plot data correctly with tab delimited text files?

I'm not sure if I have misunderstood the concept of mesh, seeing as I'm fairly new to programming in MATLAB again. I've been trying to get MATLAB to graph data that I've gotten from a Monte Carlo N particle simulation (MCNPX) and have managed, with some struggle, to get the program to output a file of the form:

X_Value Z_Value  Flux Error
-6.93000  -6.93000  0.244128E-05  0.235944

And so on iterating down to a full grid value of +7 respectively where all gaps are separated by tabs and all values for Flux are between E-05 and E-01.

My problem is when I use mesh in the following way:

tdfread
Data = [X_Value, Z_Value, Flux];
mesh(Data);
xlabel('X axis');
ylabel('Z axis');

I end up with a hideous mess with all the wrong values, wrong scaling, etc. Similarly there is another program which I can use to extract the binary data directly from the data files I am using but the way the data is referenced is confusing. I will include this information later on if I have no way to proceed directly.

[Nicholas]

I should note that I managed to plot something in plot3 but I would like to achieve the same result in mesh3 due to it running faster and being prettier for diagrams.

[Walter Roberson]

Do your X and Z values form a full grid? So that for each combination of unique X value and unique Z value, there is a Flux ?

If your data does not form a full grid then mesh() is not appropriate, at least not without some pre-processing.