9 replies to this topic

[Martin Gamache]

Anyone know of a free utility/plug in to get a frequency count from a table column in Arc. I know that the Frequency tool can do this but it requires an Arc Info license....anyone know of another tool that can do this?

mg




later......

Found this script:
http://arcscripts.es....asp?dbid=14173

[peanut]

You can right click on the field you want to get the frequency for and select Summarize...

This will give you a table with each distinct entity in your field and the count of the number of times it occurs. You can also do something similiar to this using the dissolve tool in ArcTool box if you need the counts in the same attribute table with your other tabular data.

Hope this helps.

Rich

[Matthew Hampton]

If you have the old version of ArcView - xtools does the trick.

[paul]

XTools for ArcGIS 9.x will do it too. Registration is not free, but you can get a 30-day trial.

[Martin Gamache]

I have x-tools but I couldn't find a tool to get that kind of count, summary statistics and ultimately generate a histogram.

Maybe I didn't look closely enough.

mg

[paul]

I have x-tools but I couldn't find a tool to get that kind of count, summary statistics and ultimately generate a histogram.

Maybe I didn't look closely enough.

mg

In XTools for Arc9.x, click on the menu-->Table Operations-->Aggregate Features/Records. Select your feature layer or table, the field(s) you want to summarize, and then select "Count" for any other field. The field you select the count for is usually arbitary; it will simply tally the number of features in each of your summary field categories. Not sure if I explained that well, but hope it helps.

This aggregate operation is the one and only reason we have XTools licenses.

[Martin Gamache]

Paul,

I ended up using this tool alot for a project today. It is quite powerful. Took me a little bit to figure out to duplicate a field if I wanted to both sort by it and get counts of individual values in it. But once I did it worked beautifully.

mg

[paul]

Paul,

I ended up using this tool alot for a project today. It is quite powerful. Took me a little bit to figure out to duplicate a field if I wanted to both sort by it and get counts of individual values in it. But once I did it worked beautifully.

mg

Glad it worked out for you. I use it nearly every day.

BTW - you don't need to duplicate the field to get a count; you can just calculate the count on ANY field, and it will work fine, since all it does is count rows in the table, not table values themselves. So once you select the field to sort by, the count field is actually arbitrary.

[frax]

just for the record, I would have used MS Access for this kind of operation, with the full power of SQL. Or the SDE host database, if this was an enterprise geodatabase (which could be accessed through Access as the frontend).

If this was a shapefile, it is easy to add the dbf as a linked table in Access, if it is a personal gdb, then it is already in access...

[MapMedia]

I found this...

I need to get a frequency (count) of how many times a value appears in my table. Can I do this in ArcMap?
Yes, this functionality is part of the summarize function. When your field is defined as a Text field, the returned summary information is a frequency count for the selected field. Open the attribute table of the desired layer. Right click on the column you wish to count, and choose 'Summarize '. The dialog will allow you to add additional fields for summation, computing averages etc. If you don?t need any of this, leave the middle section blank. Make sure to create a file name that you will remember, the default name is 'Sum_output'. If you have records selected in your table, you can choose to only generate summary statistics for those.

You will be prompted ?Do you want to add the result table in the map??. Click Yes.

The output table will contain a unique list of values for the selected field, and a Count column, indicating the number of times that value appears in the table. You might then wish to join this table to a shape file to use these frequency counts as a quantitative value on a map.

source: http://www.dhss.mo.gov/GIS/Faq.html#t4