If you have a new Vista-style start menu, just enter cmd. This will open up the command-line interface, also known as the "DOS prompt". Now, change directories in the command-line interface to wherever your NetCDF data is located. It will probably be helpful to have a look at how the data is organized. Type ncdump -h filename and you should get a page of output that looks something like this.
This is the metadata for your file, telling you everything about how the data in the file is structured, like the names of the different variables, plus a lot of ancillary information such as units. To extract the data, you just need to know the name of the variable and the array indices of the grid cell you want to extract. You can extract values for a range of coordinates, but if your range was, say, 2 cells high and 3 wide, the resulting output would be blocks of 2x3 numbers, separated by blank lines.
You may find this format useful to view, but it's not very good for importing into programs like Excel, and you will in many cases be better off working with a separate file for each gridcell. Let's say you're interested in climate in the eastern half of Nebraska.
I'm going to run through an example for the point nearest the tri-state intersection of Nebraska, South Dakota, and Iowa—right near Sioux City. Suppose we want to plot temperature versus time using Excel. It's always a good idea to sanity-check the data to make sure that the extracted values make numerical sense by doing something like making a simple plot. Then, download the data file. Next, we find the indices of the grid cell of interest.
It has coordinates 43, Recall that these coordinates will only work for WRFG data; other models will have different gridcell coordinates for this location. Now we open a command window and have a look at the headers. We can see that the main data variable is named 'tas' and has units of degrees Kelvin. The first four values are: Any thoughts?
Improve this question. Julien Chastang Add a comment. Active Oldest Votes. This seems to have gone missing in the latest version of the TDS 4. So if don't see the vertical level specifier, you can still specify a certain level by adding it manually to the URL.
The vertical selector works fine for data with dimensional coordinaets, but For dimensionless vertical coordinate models, even if they are CF-Compliant, the service is currently is not converting to dimensional coordinates.
So the user receives the dimensionless coordinate back, and also must specify the dimensionless coordinate if they want a particular level. This is obviously not very useful. If the user specifies a level above or below the levels in the dataset, the data value that is returned is a NaN. So for an ocean model, if you enter a value of 0, thinking that you will get the surface layer, you might get a NaN, because the level of the surface layer might be I have reported all of these issues to Unidata.
Improve this answer. I've tried to write a simple C console app which just reads the file and writes it out to the console or ideally to a. If I comment out the var Times If I use SByte it complains that the variable doesn't exist.
If I use Int32 it complains about converting to string. I think I have solved the puzzle. The problem is that the 2nd variable is empty. I'm not sure if that is by accident or design. I have found the Date of when data is supposed to start in a meta data field. I've modified my code now so that it retrieves this, and writes it all to the console. I've really struggled with this so I'm sharing this in the hope it will be of use to someone else. One thing I really found useful was the discussion tab on Codeplex as it has lots of useful code snippets.
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