[ncl-talk] avoiding loops

[Micah Sklut]

This worked great Dave. I appreciate the great support. I did the asciiread
to read back in all the string arrays, and then used write_table to format
the final output.

One last question. When formating the write_matrix calls, I'm trying to
write a float variable to integer format.  When I use, floattointeger
function, it properly converts the values to integers, however, it doesn't
change the variable type in the metadata from float to integer. This
doesn't allow me to write_matrix using integer format. Is there an easy way
to get around this?

On Sun, Sep 22, 2019 at 8:31 PM Dave Allured - NOAA Affiliate <
dave.allured at noaa.gov> wrote:

> Write_matrix is strictly for output to only a text file, or Unix standard
> output.  There is no internal write capability.  However, you can simulate
> internal writes by using one or more temporary files.
>
> Read the formatted lines back in from a temp file with asciiread
> ("tmp.txt", -1, "string").  This gives you a 1-D array of strings, one full
> line for each of your grid points.  Then repeat for each of your other
> variables.  This will efficiently give you arrays of full formatted line
> strings for several variables.
>
> You should then be able to join these line strings together, however you
> have in mind.  Also, now that you are operating on strings, you can add
> text columns at the beginning or end of each string, if this would be of
> any help.  For example:
>
> long_lines = "precip," + p_lines(:) + ",Tmin," + tmin_lines(:) +
> ",Tmax," + tmax_lines(:)
>
> This example is for joining horizontally.  You could also join vertically
> by simply joining the string arrays, with or without interleaving.  There
> are many variations on this theme, depending on how you want your final
> output to be structured.
>
>
> On Sun, Sep 22, 2019 at 5:29 PM Micah Sklut <micahs2005 at gmail.com> wrote:
>
>> Instead of sending output to a file, is it possible to do a write_matrix
>> formatting to 1d array?  I need to add more than 1 of these variables
>> together, so if I can create 1d arrays for all of the variables and
>> metadata, such as lat/lon, then I can use write_table to join everything
>> together. When I'm re-ordering or reshaping the arrays, I'll just need to
>> delete the old arrays, to free up memory.
>>
>> On Sun, Sep 22, 2019 at 1:51 PM Dave Allured - NOAA Affiliate <
>> dave.allured at noaa.gov> wrote:
>>
>>> There is a mistake in the untested example that I sent.  Please change
>>> the format spec from "384(f0.1,','),f0.1" to "383(f0.1,','),f0.1".  The
>>> latter is correct for 384 numbers per line.  I split the format spec into
>>> two parts so that there would not be a trailing comma at the end of each
>>> line.
>>>
>>> Generally speaking, the format spec in write_matrix is specified for a
>>> single output line.  It is repeated for each output line.  It is important
>>> that the total item count in the format spec (383 + 1 in this case) exactly
>>> matches the intended number of items per line.
>>>
>>>
>>> On Sun, Sep 22, 2019 at 11:32 AM Micah Sklut <micahs2005 at gmail.com>
>>> wrote:
>>>
>>>> Okay, thanks, Dave.  That sounds like what I need. I've always
>>>> struggled with the formatting in NCL, but I'll give that a go and see where
>>>> I get.
>>>>
>>>> On Sun, Sep 22, 2019 at 1:26 PM Dave Allured - NOAA Affiliate <
>>>> dave.allured at noaa.gov> wrote:
>>>>
>>>>> Try write_matrix and the F0 format descriptor.  F0 format is part of
>>>>> fortran 90 and up.  It is described in modern fortran documentation.  It is
>>>>> like the common Fw.d format descriptor, except leading blanks to the left
>>>>> of the decimal point are suppressed.
>>>>>
>>>>> Reshape your array from, e.g. (lat,lon,time), to a 2-D array in the
>>>>> desired output order, (points,time).  Npoints = Nlats x Nlons.  Then a
>>>>> single call to write_matrix should write the entire output file:
>>>>>
>>>>>     opt = True
>>>>>     opt at fout = "temperature.csv"
>>>>>     write_matrix (data_out, "384(f0.1,','),f0.1", opt)
>>>>>
>>>>> You can add arbitrary extra numeric columns to the output array, if it
>>>>> would be helpful to have lats and lons, or other such metadata, on each
>>>>> line of output.
>>>>>
>>>>>
>>>>> On Sat, Sep 21, 2019 at 2:53 PM Micah Sklut via ncl-talk <
>>>>> ncl-talk at ucar.edu> wrote:
>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> I have a task to take GFS data and concatenate variables across all
>>>>>> the forecast hours, for each grid point.
>>>>>>
>>>>>> For example, taking a temperature variable for each grid point, for
>>>>>> all latitude and longitudes, and creating a string that represents the
>>>>>> values for each forecast hour.
>>>>>> So, if we have for latitude y, and longitude x, there would be a
>>>>>> string value like "70.5,71.5,71.5,72.0,...nHours".  The end product will be
>>>>>> a line for each grid point for the variables i"m looking at that will be
>>>>>> written to a file to be imported into a database.
>>>>>>
>>>>>> Creating loops through all hours, latitudes, and longitudes will get
>>>>>> the job done, but is expensive and was looking to see if there were any NCL
>>>>>> functions that would help here.
>>>>>>
>>>>>> Thank you.
>>>>>>
>>>>>

-- 
Micah Sklut
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20190923/9fb43dfd/attachment.html>