This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
No problem - that's why we're here! :-) Also, you may be interested in our IDV workshop, which is going to be in October this year. Feel free to check out the workshop page if you're interested. http://www.unidata.ucar.edu/events/2012TrainingWorkshop/ Cheers, Sean > Thanks for all of your generous help Sean. > > I hope I don't have to send you my file for header maintenance after future > computations. ;) > > Thanks again, > > Patrick > ________________________________________ > From: Unidata IDV Support [address@hidden] > Sent: Thursday, July 26, 2012 2:15 PM > To: Patrick C. Campbell > Cc: address@hidden > Subject: [IDV #YHN-171651]: Loading Point Data File: > java.lang.NullPointerException > > Awesome - I'm glad it worked out! Now for the fun part...computations! > > Best of luck, > > Sean > > > Sean, > > > > OK, I changed the date. I also opened the EXCEL saved CSV file as a text > > document, and noticed that EXCEL added a bunch of erroneous quotation marks > > when saving. If I get rid of these too, then IDV can now read the file. > > The added quotation marks cannot be seen unless opening in WordPad or > > something. > > > > Now for computing new variables into the file, without trying to screw up > > the header. ;) > > > > Thanks, > > > > Patrick > > ________________________________________ > > From: Unidata IDV Support [address@hidden] > > Sent: Thursday, July 26, 2012 2:08 PM > > To: Patrick C. Campbell > > Cc: address@hidden > > Subject: [IDV #YHN-171651]: Loading Point Data File: > > java.lang.NullPointerException > > > > Hi Patrick, > > > > The file that the IDV outputs uses the following format (as written in > > the header): > > > > Time[fmt="yyyy-MM-dd HH:mm:ss"] > > > > and the time stamps appear in the file as: > > > > 2010-06-23 03:00:00 > > > > Given that the format from the header and the way the time stamps are > > structured in the data match, the IDV has no problem. > > > > However, when you load the file into Excel and then save as CSV, > > the format (as written the header) is still listed as: > > > > Time[fmt=""yyyy-MM-dd HH:mm:ss""] > > > > but the time stamps in the data actually look like > > > > 6/23/2010 3:00 > > > > because Excel changed your time stamps to its default. > > > > Sean > > > > > Sean, > > > > > > I will try that. So your saying once I save it again as .CSV EXCEL > > > changes the date format? Funny, I looked at that, and if I don't save it > > > all, IDV still reads it in OK with the incorrect date format. > > > > > > For example, attached is a file that I just exported from IDV without > > > saving it externally. IDV can read this file unless I try to externally > > > save it as a CSV. > > > > > > Thanks, > > > Patrick > > > ________________________________________ > > > From: Unidata IDV Support [address@hidden] > > > Sent: Thursday, July 26, 2012 1:51 PM > > > To: Patrick C. Campbell > > > Cc: address@hidden > > > Subject: [IDV #YHN-171651]: Loading Point Data File: > > > java.lang.NullPointerException > > > > > > Hi Patrick, > > > > > > I see from the other support question that you were using Excel to > > > manipulate the CSV > > > file. It looks like Excel changed the format of your date/time stamps in > > > the data, thus > > > making you header incorrect. Make sure you tell Excel to use the proper > > > date format, > > > > > > yyyy-MM-dd HH:mm:ss > > > > > > before you export to CSV. > > > > > > Cheers, > > > > > > Sean > > > > > > PS: Sorry for the duplicate email - just want to make sure this doesn't > > > get lost. > > > > > > > Hi Sean, > > > > > > > > Thank you for responding. OK, here is what I do to reserve and save > > > > the file: > > > > > > > > 1) Use your method to load the Mesowest data using the "Mesowest > > > > Chooser Plugin" in IDV. I choose a region surrounding the Rocky > > > > Mountains for June 23, 2010 - 03:00 GMT, all observations, back -12 > > > > hours. > > > > 2) Under the Field Selector tab, point cloud is available, I choose > > > > point data, and then choose to display a Point Data List. > > > > 3) Under the Display tab, I then go to "Select Fields" and choose all > > > > the variables. Under File, I choose Save and then Export Table to CSV. > > > > 4) If I immediately try to read the new CSV, it works OK. > > > > 5) Or, if I save the exported CSV within EXCEL, then try to read in > > > > IDV, it doesn't work. > > > > > > > > Hope this helps, > > > > > > > > Patrick > > > > > > > > ________________________________________ > > > > From: Unidata IDV Support [address@hidden] > > > > Sent: Thursday, July 26, 2012 1:06 PM > > > > To: Patrick C. Campbell > > > > Cc: address@hidden > > > > Subject: [IDV #YHN-171651]: Loading Point Data File: > > > > java.lang.NullPointerException > > > > > > > > Hi Patrick, > > > > > > > > The header in the file you sent me was indeed messed up. When you > > > > reserved the file, > > > > how exactly did you do it? > > > > > > > > Sean > > > > > > > > > Thanks Sean. > > > > > > > > > > One more issue. I have been in contact with a Yuan at your IDV > > > > > support. He mentioned to me that if I wanted to make edits to a > > > > > point data file, I could not use Jython functions within IDV, but > > > > > rather export the IDV Mesowest data to a .CSV file, edit it, then > > > > > re-read it into IDV. > > > > > > > > > > When testing the export of the .CSV file and re-reading in IDV, it > > > > > works OK. However, when exporting the .CSV file, and re-saving it > > > > > as .CSV with no edits applied to either the data or headers, IDV > > > > > won't read it. > > > > > > > > > > There was an error loading the data: > > > > > java.lang.NullPointerException > > > > > > > > > > > > > > > The exported and saved .CSV file is attached. Since you noted that > > > > > my last header was missing a few things, it seems like there is an > > > > > issue with this header. However, this is exactly how IDV exports it > > > > > to a .CSV file? > > > > > > > > > > Any insight would be much appreciated. > > > > > > > > > > Patrick > > > > > ________________________________________ > > > > > From: Unidata IDV Support [address@hidden] > > > > > Sent: Wednesday, July 25, 2012 7:52 AM > > > > > To: Patrick C. Campbell > > > > > Cc: address@hidden > > > > > Subject: [IDV #YHN-171651]: Loading Point Data File: > > > > > java.lang.NullPointerException > > > > > > > > > > Greetings Patrick, > > > > > > > > > > It looks like your header was missing a few things. Here is a header > > > > > that works for your data file: > > > > > > > > > > (index)->(Time,Station(Text),Latitude,Longitude,Altitude,MNETID(Text),Mesonet(Text),T,RH,WSPD,WDIR,PSL,ALTI,TD) > > > > > Time[fmt="yyyy-MM-dd > > > > > HH:mm"],Station(Text)[],Latitude[unit="degrees"],Longitude[unit="degrees"],Altitude[unit="foot"],MNETID(Text)[],Mesonet(Text)[],T[unit="Celsius" > > > > > missing="-9999"],RH[unit="percent" missing="-9999"],WSPD[unit="kt" > > > > > missing="-9999"],WDIR[unit="degrees" missing="-9999"],PSL[unit="Pa" > > > > > missing="-9999"],ALTI[unit="Pa" missing="-9999"],TD[unit="Celsius" > > > > > missing="-9999"] > > > > > > > > > > Cheers! > > > > > > > > > > Sean > > > > > > > > > > > Sean, > > > > > > > > > > > > Thank you for taking a look. Also, I didn't know about the > > > > > > "Mesowest Chooser", nor the plugin category. This is excellent! > > > > > > Maybe I need a IDV tutorial someday. > > > > > > > > > > > > Patrick > > > > > > ________________________________________ > > > > > > From: Unidata IDV Support [address@hidden] > > > > > > Sent: Monday, July 23, 2012 4:30 PM > > > > > > To: Patrick C. Campbell > > > > > > Cc: address@hidden > > > > > > Subject: [IDV #YHN-171651]: Loading Point Data File: > > > > > > java.lang.NullPointerException > > > > > > > > > > > > Greetings Patrick, > > > > > > > > > > > > I'll be happy to take a look at this. However, did you know that > > > > > > the IDV has a MesoWest > > > > > > data chooser plugin available? If you click "Tools -> Plugin > > > > > > Manager" and select the > > > > > > "Mesowest Chooser" from the "Data Sources" plugin category, you'll > > > > > > be able to load > > > > > > Mesowest data from the Data Choosers interface on the IDV Dashboard. > > > > > > > > > > > > Cheers, > > > > > > > > > > > > Sean > > > > > > > > > > > > > Full Name: Patrick Campbell > > > > > > > Email Address: address@hidden > > > > > > > Organization: University of Wyoming > > > > > > > Package Version: 3.0u2 build date:2012-02-10 17:21 UTC > > > > > > > Operating System: Windows 7 > > > > > > > Hardware: Java: home: C:\Program Files\IDV_3.0u2\jre version: > > > > > > > 1.6.0_20 j3d:1.5.2 fcs (build4) > > > > > > > Description of problem: Hello, > > > > > > > > > > > > > > Below is the error I am receiving when trying to load a simple > > > > > > > point data file. > > > > > > > > > > > > > > There was an error loading the data: > > > > > > > java.lang.NullPointerException > > > > > > > > > > > > > > I downloaded the data file in .xls format from the Mesowest > > > > > > > website, and then changed the extension to a .csv format. > > > > > > > Subsequently, I manipulated the file to match what I thought was > > > > > > > a suitable format. Please see the attached point data file. I > > > > > > > would appreciate any input on this matter. > > > > > > > > > > > > > > Regards, > > > > > > > > > > > > > > Patrick Campbell > > > > > > > > > > > > > > There was an error loading the data: > > > > > > > java.lang.NullPointerException > > > > > > > > > > > > > > ****************** > > > > > > > Stack trace: > > > > > > > java.lang.NullPointerException > > > > > > > at visad.Tuple.buildTupleType(Tuple.java:170) > > > > > > > at > > > > > > > ucar.unidata.data.point.TextPointDataSource.makePointObs(TextPointDataSource.java:2105) > > > > > > > at > > > > > > > ucar.unidata.data.point.TextPointDataSource.makeObs(TextPointDataSource.java:656) > > > > > > > at > > > > > > > ucar.unidata.data.point.TextPointDataSource.makeObs(TextPointDataSource.java:479) > > > > > > > at > > > > > > > ucar.unidata.data.point.TextPointDataSource.getSample(TextPointDataSource.java:2518) > > > > > > > at > > > > > > > ucar.unidata.data.point.PointDataSource.doMakeDataChoices(PointDataSource.java:939) > > > > > > > at > > > > > > > ucar.unidata.data.point.TextPointDataSource.doMakeDataChoices(TextPointDataSource.java:2526) > > > > > > > at > > > > > > > ucar.unidata.data.DataSourceImpl.getDataChoices(DataSourceImpl.java:1839) > > > > > > > at > > > > > > > ucar.unidata.data.DataManager.createDataSource(DataManager.java:1579) > > > > > > > at > > > > > > > ucar.unidata.idv.IntegratedDataViewer.createDataSource(IntegratedDataViewer.java:1980) > > > > > > > at > > > > > > > ucar.unidata.idv.IntegratedDataViewer.makeDataSource(IntegratedDataViewer.java:1897) > > > > > > > at > > > > > > > ucar.unidata.idv.IntegratedDataViewer.makeDataSource(IntegratedDataViewer.java:1831) > > > > > > > at > > > > > > > ucar.unidata.idv.IntegratedDataViewer.makeDataSource(IntegratedDataViewer.java:1804) > > > > > > > at > > > > > > > ucar.unidata.idv.chooser.IdvChooser.makeDataSource(IdvChooser.java:943) > > > > > > > at > > > > > > > ucar.unidata.idv.chooser.FileChooser.selectFilesInner(FileChooser.java:656) > > > > > > > at > > > > > > > ucar.unidata.idv.chooser.FileChooser.selectFiles(FileChooser.java:525) > > > > > > > at > > > > > > > ucar.unidata.idv.chooser.FileChooser.doLoadInThread(FileChooser.java:547) > > > > > > > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > > > > > > > at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) > > > > > > > at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) > > > > > > > at java.lang.reflect.Method.invoke(Unknown Source) > > > > > > > at ucar.unidata.util.Misc$2.run(Misc.java:1062) > > > > > > > at ucar.unidata.util.Misc$3.run(Misc.java:1090) > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Ticket Details > > > > > > =================== > > > > > > Ticket ID: YHN-171651 > > > > > > Department: Support IDV > > > > > > Priority: Normal > > > > > > Status: Open > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Ticket Details > > > > > =================== > > > > > Ticket ID: YHN-171651 > > > > > Department: Support IDV > > > > > Priority: Normal > > > > > Status: Closed > > > > > > > > > > > > > > > > > > > > > > > > > > > Ticket Details > > > > =================== > > > > Ticket ID: YHN-171651 > > > > Department: Support IDV > > > > Priority: Normal > > > > Status: Open > > > > > > > > > > > > > > > > > > > > > Ticket Details > > > =================== > > > Ticket ID: YHN-171651 > > > Department: Support IDV > > > Priority: Normal > > > Status: Open > > > > > > > > > > > > > > > Ticket Details > > =================== > > Ticket ID: YHN-171651 > > Department: Support IDV > > Priority: Normal > > Status: Open > > > > > > > > > Ticket Details > =================== > Ticket ID: YHN-171651 > Department: Support IDV > Priority: Normal > Status: Closed > > > Ticket Details =================== Ticket ID: YHN-171651 Department: Support IDV Priority: Normal Status: Closed