[ncl-talk] Issue with creating a bar chart plot
Andrew Kren - NOAA Affiliate
andrew.kren at noaa.gov
Fri Jun 12 09:49:42 MDT 2020
All,
I was able to reproduce the error that Rick found with the reference line.
Is there any way to fix this by still having a reference line?
On Tue, Jun 9, 2020 at 5:07 PM Andrew Kren - NOAA Affiliate <
andrew.kren at noaa.gov> wrote:
> Thanks Rick! Hmm, that is interesting. Could it be that I used an array of
> reference lines? This would make some sense as the previous NCL version I
> used was 6.5 and didn't upgrade the newer version until last year. I'll try
> to dig on my end as well.
>
> On Tue, Jun 9, 2020 at 9:39 AM Rick Brownrigg <brownrig at ucar.edu> wrote:
>
>> (back online)
>>
>> Hi Andrew,
>>
>> The errors have to do indirectly with the reference line; If I remove
>> those resources, I get a histogram without error messages being thrown. I
>> was able to track precisely where in the code things go awry, however I do
>> not understand the logic leading up to that point, so I really don't know
>> what is the real problem. I unfortunately do not have time to dig into this
>> at the level it would require to understand this code (oh for an
>> interactive ncl debugger).
>>
>> There were some changes to gsn_csm.ncl that dealt with reference lines
>> around the 2017-2018 time frame, but they seem to be minor and not directly
>> related to the code where the miscalculation of box widths occurs, so
>> again, its hard to tell.
>>
>> I wish I had a better answer
>> Rick
>>
>> On Tue, Jun 9, 2020 at 5:46 AM Andrew Kren - NOAA Affiliate <
>> andrew.kren at noaa.gov> wrote:
>>
>>> Hi Rick,
>>>
>>> Here is a functioning code. I just saved the plotting section and made
>>> my own test array, giving the same error. I know I don't need to convert to
>>> integer in my min and max calculation but that shouldn't matter.
>>>
>>> Thanks,
>>>
>>> On Mon, Jun 8, 2020 at 10:05 PM Rick Brownrigg <brownrig at ucar.edu>
>>> wrote:
>>>
>>>> Offline for the moment -- Andrew if you can send me the data and a
>>>> functionally complete script, I'll try to dig into it deeper.
>>>>
>>>> On Mon, Jun 8, 2020 at 6:31 PM Andrew Kren - NOAA Affiliate <
>>>> andrew.kren at noaa.gov> wrote:
>>>>
>>>>> Hi ncl-talk, Dave, and Rick,
>>>>>
>>>>> I took both of your guys' advice and here is what I found. I first
>>>>> removed tolong but that did not fix it. I then tried dong rounding, as well
>>>>> as not doing any conversion, but that still resulted in the error. Then I
>>>>> tried commenting out the defining of the bar chart width, but it still came
>>>>> up with the same error:
>>>>>
>>>>> (0) get_bar_arrays: Fatal: The array is not monotonically increasing.
>>>>>
>>>>> (0) Cannot draw a bar chart.
>>>>>
>>>>> fatal:Illegal right-hand side type for assignment
>>>>>
>>>>>
>>>>> Here is what I have for my plot section:
>>>>>
>>>>>
>>>>> outfile = "fcst_efuuyr3wd6_top_1_" + (i)
>>>>>
>>>>>
>>>>> length1 = temperature_top(i,0:23)
>>>>>
>>>>>
>>>>> wks = gsn_open_wks("eps",outfile) ; send graphics to PNG file
>>>>>
>>>>> res = True
>>>>>
>>>>> res at gsnScale = True
>>>>>
>>>>> res at gsnFrame = False
>>>>>
>>>>> res at gsnDraw = True
>>>>>
>>>>> ; these four resources allow the user to stretch the plot size, and
>>>>>
>>>>> ; decide exactly where on the page to draw it.
>>>>>
>>>>>
>>>>> ;res at gsnMaximize = True
>>>>>
>>>>> res at vpXF = 0.01 ; In page coordinates, where to start
>>>>>
>>>>> res at vpYF = 0.9 ; 0.75 ; the plot
>>>>>
>>>>> res at vpHeightF = 0.27 ; Changes the aspect ratio
>>>>>
>>>>> res at vpWidthF = 0.97
>>>>>
>>>>>
>>>>> x_axis = ispan(4,73,3)
>>>>>
>>>>> x_axis at _FillValue = 999
>>>>>
>>>>>
>>>>>
>>>>> res at tiMainString = names_14ers(i) + " 3-Day Forecast (Peak: " +
>>>>> hgts_14ers_str(i) + " ft)"
>>>>>
>>>>> res at gsnXYBarChart = True ; Create bar plot
>>>>>
>>>>> res at tiMainOffsetYF = 0.006
>>>>>
>>>>> res at tiMainFontHeightF = 0.02
>>>>>
>>>>> res at tmXTMode = "Explicit" ; Define own tick mark labels.
>>>>>
>>>>> res at tmXTValues = x_axis
>>>>>
>>>>> res at tmXTOn = False ; turn on the top tickmarks
>>>>>
>>>>> res at tmXBOn = False
>>>>>
>>>>> res at tmYROn = False
>>>>>
>>>>> res at tmYRMinorOn = False
>>>>>
>>>>> res at tmYLOn = False
>>>>>
>>>>> res at tmYLMinorOn = False
>>>>>
>>>>> res at tmXTMinorOn = False
>>>>>
>>>>> res at gsnXRefLine = (/26.5,50.5/)
>>>>>
>>>>> res at gsnXRefLineColor = (/"gray40","gray40"/)
>>>>>
>>>>> res at gsnXRefLineDashPatterns = (/2,2/)
>>>>>
>>>>> res at gsnXRefLineThicknesses = (/1.05,1.05/)
>>>>>
>>>>> res at tiYAxisOffsetXF = 0.035
>>>>>
>>>>> res at tiYAxisString = "Temperature"
>>>>>
>>>>>
>>>>> res at tiYAxisFontHeightF = 0.014
>>>>>
>>>>>
>>>>> range_temp = ( tofloat( max(tolong(temperature_top(i,0:23))) -
>>>>> min(tolong(temperature_top(i,0:23)))))
>>>>>
>>>>> max_temp = tofloat(max(tolong(temperature_top(i,0:23)))) +
>>>>> (tofloat(max(tolong(temperature_top(i,0:23))) -
>>>>> min(tolong(temperature_top(i,0:23))))) * 0.8
>>>>>
>>>>> min_temp = tofloat(min(tolong(temperature_top(i,0:23)))) -
>>>>> (tofloat(max(tolong(temperature_top(i,0:23))) -
>>>>> min(tolong(temperature_top(i,0:23))))) * 0.1
>>>>>
>>>>>
>>>>> res at trYMaxF = max_temp ; max value on y-axis
>>>>>
>>>>> res at trYMinF = min_temp
>>>>>
>>>>> ; res at gsnXYBarChartBarWidth = 0.75 ; change bar
>>>>> widths 0.75 originally
>>>>>
>>>>> res at gsnXYBarChartColors = "Orange"
>>>>>
>>>>>
>>>>> ; draw 5 separate temperature plots so can make figure big
>>>>>
>>>>> res at trXMinF = 0 ; adds space on
>>>>> either end
>>>>>
>>>>> res at trXMaxF = 75 ; of the 1st and
>>>>> last bars
>>>>>
>>>>>
>>>>> plot = gsn_csm_xy(wks,x_axis,temperature_top(i,0:23),res)
>>>>>
>>>>>
>>>>> My x_axis values are: 4 to 73 by 3
>>>>>
>>>>> My temperature_top values are:
>>>>>
>>>>>
>>>>> (0) 14
>>>>>
>>>>> (1) 11
>>>>>
>>>>> (2) 11
>>>>>
>>>>> (3) 12
>>>>>
>>>>> (4) 14
>>>>>
>>>>> (5) 21
>>>>>
>>>>> (6) 24
>>>>>
>>>>> (7) 23
>>>>>
>>>>> (8) 23
>>>>>
>>>>> (9) 22
>>>>>
>>>>> (10) 23
>>>>>
>>>>> (11) 26
>>>>>
>>>>> (12) 33
>>>>>
>>>>> (13) 36
>>>>>
>>>>> (14) 33
>>>>>
>>>>> (15) 28
>>>>>
>>>>> (16) 25
>>>>>
>>>>> (17) 25
>>>>>
>>>>> (18) 25
>>>>>
>>>>> (19) 29
>>>>>
>>>>> (20) 38
>>>>>
>>>>> (21) 41
>>>>>
>>>>> (22) 39
>>>>>
>>>>> (23) 35
>>>>>
>>>>>
>>>>> I don't understand why the error could still be happening.
>>>>>
>>>>>
>>>>> Thanks,
>>>>>
>>>>> On Mon, Jun 8, 2020 at 1:40 PM Dave Allured - NOAA Affiliate <
>>>>> dave.allured at noaa.gov> wrote:
>>>>>
>>>>>> Andrew,
>>>>>>
>>>>>> In the face of unknown behavior, I would try a couple things. First,
>>>>>> go back to your original code without my previous suggestion of reversing
>>>>>> the axes. That was based on a wrong assumption.
>>>>>>
>>>>>> 1. I do not understand the purpose of "tolong" here. Data type
>>>>>> "long" is normally used only for special purposes in NCL, and there is a
>>>>>> chance it is causing trouble. Also, "tolong" would reduce plot accuracy by
>>>>>> integer truncation. Try simply removing "tolong", and use
>>>>>> temperature_top(i,0:23) directly in the function call. Tofloat, todouble,
>>>>>> or toint would be safer alternatives if a conversion function is really
>>>>>> needed. If you really want integer rounding here, then you should use the
>>>>>> round function to reduce roundoff error.
>>>>>>
>>>>>> 2. Try completely isolating the plot function from the rest of the
>>>>>> program. Write the X and Y arrays to a small Netcdf file. Print (res) and
>>>>>> manually recode the printed results into new NCL code lines in a small new
>>>>>> test program. Omit all "res" attributes that are not relevant for this
>>>>>> plot type. Read the Netcdf file, then call open_wks and gsn_csm_xy, and
>>>>>> see if the problem remains. This way, at least you end up with a small
>>>>>> reproducer and small data that you can send to the mailing list. HTH.
>>>>>>
>>>>>>
>>>>>> On Mon, Jun 8, 2020 at 7:17 AM Rick Brownrigg <brownrig at ucar.edu>
>>>>>> wrote:
>>>>>>
>>>>>>> I took a quick look at the code. As the errors indicate, it's
>>>>>>> happening in a function call get_bart_width(). The calculation of the
>>>>>>> variable "delta" is clearly wrong, and that sets off the warning, and
>>>>>>> triggers the error later in get_bar_arrays about non-monotonicity (it's
>>>>>>> actually not that the array is non-monotonic, it's that it has negative
>>>>>>> widths).
>>>>>>>
>>>>>>> Beyond that, I can not tell why the calculation is wrong,
>>>>>>> particularly without the data. That part of the code hasn't changed in some
>>>>>>> years, so the v6.5.0 vs v6.6.2 difference is a mystery.
>>>>>>>
>>>>>>> FWIW...
>>>>>>> Rick
>>>>>>>
>>>>>>>
>>>>>>> On Sun, Jun 7, 2020 at 6:58 PM Andrew Kren - NOAA Affiliate via
>>>>>>> ncl-talk <ncl-talk at mailman.ucar.edu> wrote:
>>>>>>>
>>>>>>>> I looked into these things. My x_axis is simply created this way:
>>>>>>>>
>>>>>>>> x_axis = ispan(4,73,3)
>>>>>>>>
>>>>>>>>
>>>>>>>> And the printed values are correct, increasing by 3 starting at 4,
>>>>>>>> 7, etc.
>>>>>>>>
>>>>>>>>
>>>>>>>> So this is still kinda confusing as to why.
>>>>>>>>
>>>>>>>> On Sun, Jun 7, 2020 at 5:41 PM Dave Allured - NOAA Affiliate <
>>>>>>>> dave.allured at noaa.gov> wrote:
>>>>>>>>
>>>>>>>>> It is only the horizontal axis that needs to be monotonically
>>>>>>>>> increasing. That is probably what the error message is about. Naturally,
>>>>>>>>> the vertical access may fluctuate anywhere. You might want to check the
>>>>>>>>> values of x_axis in your code to see if they make sense.
>>>>>>>>>
>>>>>>>>> Meanwhile, you should be able to insert a quick fix for x_axis
>>>>>>>>> with temporary arrays, something like this. This assumes that x_axis is
>>>>>>>>> strictly decreasing rather than increasing. If you change the order, then
>>>>>>>>> you must also change the order for the vertical axis data, in the same
>>>>>>>>> way. X and Y values are supposed to form ordered pairs to make the bar
>>>>>>>>> chart.
>>>>>>>>>
>>>>>>>>> xplot = x_axis(::-1)
>>>>>>>>> yplot = tolong (temperature_top(i,23:0:-1))
>>>>>>>>> plot = gsn_csm_xy (wks, xplot, yplot, res)
>>>>>>>>>
>>>>>>>>> I have no idea what changed to cause a newer NCL version to change
>>>>>>>>> from the original behavior.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Sun, Jun 7, 2020 at 1:57 PM Andrew Kren - NOAA Affiliate via
>>>>>>>>> ncl-talk <ncl-talk at mailman.ucar.edu> wrote:
>>>>>>>>>
>>>>>>>>>> Dear ncl-talk,
>>>>>>>>>>
>>>>>>>>>> I upgraded my NCL to the latest version. Previously I was using
>>>>>>>>>> version 6.5. When I upgraded, one of my ncl codes no longer runs
>>>>>>>>>> successfully but creates an error code. I am creating a bar chart with
>>>>>>>>>> gsn_csm_xy. I originally did not get these errors so I am unsure what could
>>>>>>>>>> be going on. I tried to debug the issue but to no avail. Here are my errors:
>>>>>>>>>>
>>>>>>>>>> (0) get_bar_widths: Warning: The bar width(s) you selected
>>>>>>>>>> (0.75) is larger than the smallest delta (-11).
>>>>>>>>>>
>>>>>>>>>> (0) Defaulting to -11.
>>>>>>>>>>
>>>>>>>>>> (0) get_bar_arrays: Fatal: The array is not monotonically
>>>>>>>>>> increasing.
>>>>>>>>>>
>>>>>>>>>> (0) Cannot draw a bar chart.
>>>>>>>>>>
>>>>>>>>>> fatal:Illegal right-hand side type for assignment
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> I checked that my array I am plotting has all correct values, and
>>>>>>>>>> it does. I didn't know a bar chart had to have monotonically increasing
>>>>>>>>>> values. Is there a way around this?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> The code where it fails is below, in the call to plot.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> plot = gsn_csm_xy(wks,x_axis,tolong(temperature_top(i,0:23)),res)
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> Andrew Kren
>>>>>>>>>> Meteorologist
>>>>>>>>>> US Dept of Commerce
>>>>>>>>>> National Oceanic and Atmospheric Administration
>>>>>>>>>> National Weather Service Raleigh, NC
>>>>>>>>>> 1005 Capability Drive, Suite 300
>>>>>>>>>> Centennial Campus
>>>>>>>>>> Raleigh, NC 27606-5226
>>>>>>>>>>
>>>>>>>>>
>>>>>
>>>>> --
>>>>> Andrew Kren
>>>>> Meteorologist
>>>>> US Dept of Commerce
>>>>> National Oceanic and Atmospheric Administration
>>>>> National Weather Service Raleigh, NC
>>>>> 1005 Capability Drive, Suite 300
>>>>> Centennial Campus
>>>>> Raleigh, NC 27606-5226
>>>>>
>>>>>
>>>
>>> --
>>> Andrew Kren
>>> Meteorologist
>>> US Dept of Commerce
>>> National Oceanic and Atmospheric Administration
>>> National Weather Service Raleigh, NC
>>> 1005 Capability Drive, Suite 300
>>> Centennial Campus
>>> Raleigh, NC 27606-5226
>>>
>>>
>
> --
> Andrew Kren
> Meteorologist
> US Dept of Commerce
> National Oceanic and Atmospheric Administration
> National Weather Service Raleigh, NC
> 1005 Capability Drive, Suite 300
> Centennial Campus
> Raleigh, NC 27606-5226
>
>
--
Andrew Kren
Meteorologist
US Dept of Commerce
National Oceanic and Atmospheric Administration
National Weather Service Raleigh, NC
1005 Capability Drive, Suite 300
Centennial Campus
Raleigh, NC 27606-5226
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