[ncl-talk] Issue with creating a bar chart plot
Andrew Kren - NOAA Affiliate
andrew.kren at noaa.gov
Fri Jun 12 12:22:01 MDT 2020
Hi Adam,
Thanks! So what you are saying is that it is probably better to use
gsn_add_polyline to avoid this issue? I was aware of the polyline feature,
but was hoping to not change...guess that is the best option. Thanks!
On Fri, Jun 12, 2020 at 12:22 PM Adam Phillips <asphilli at ucar.edu> wrote:
> Hi Andrew,
> Jumping in late here, and I might be off base, but you can draw as many
> lines as you want by using gsn_add_polyline:
>
> https://www.ncl.ucar.edu/Document/Graphics/Interfaces/gsn_add_polyline.shtml
>
> Functionality that depends on setting a reference line would be affected
> by this though. I would try setting one reference line, and then using
> gsn_add_polyline to draw the rest.
> Hope that helps!
> Adam
>
> On Fri, Jun 12, 2020 at 9:50 AM Andrew Kren - NOAA Affiliate via ncl-talk <
> ncl-talk at mailman.ucar.edu> wrote:
>
>> 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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>> ncl-talk at mailman.ucar.edu
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>
>
>
> --
> Adam Phillips
> Associate Scientist, Climate and Global Dynamics Laboratory, NCAR
> www.cgd.ucar.edu/staff/asphilli/ 303-497-1726
>
> <http://www.cgd.ucar.edu/staff/asphilli>
>
--
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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