Not scaling properly? Am I doing something wrong?

Community matplotlib-users
1

I'm trying what I thought was a simple test and getting "bad" results. I am taking some lat long coords, and feeding it into a map. The conversion is not giving "real" values that can be plotted on a map (and actually produces an error when I use annotate).
I'm including the simple code and the output:

CODE<<<<<<<<<<<<<<<

import pylab as p
import numpy
from matplotlib.toolkits.basemap import Basemap as Basemap
from matplotlib.colors import rgb2hex
from matplotlib.patches import Polygon

# Lambert Conformal map of lower 48 states.
# create new figure
fig=p.figure()
m1 = Basemap(llcrnrlon=-119,llcrnrlat=22,urcrnrlon=-64,urcrnrlat=49,\
            projection='ortho',lat_1=33,lat_2=45,lon_0=-95,lat_0=40,resolution='c')

#COS
#D + M/60 + S/3600
COSLat=38+56.0/60.0+0.013
COSLon=-1*(104+48.0/60.0)
WASHLat=38+53.0/60.0+23.0/3600.0
WASHLon=-1*(77+32.0/3600.0)

print COSLat
x, y = m1(COSLat,COSLon)
print 'x =%f, y=%f' % (x,y)

m1.plot(,[y],'ko')
ax=p.gca()
ax.annotate('COS1',(COSLat,COSLon))
#ax.annotate('COS2',(x,y))
ax.annotate('Wash1',(WASHLat,WASHLon))
x, y = m1(WASHLat,WASHLon)
#ax.annotate('Wash2',(x,y))

m1.drawcoastlines()
m1.fillcontinents()
m1.drawcountries()
m1.drawstates()
m1.drawparallels(numpy.arange(25,65,4),labels=[1,0,0,0])
m1.drawmeridians(numpy.arange(-120,-40,4),labels=[0,0,0,1])
p.title('full resolution')
p.show()
<<<<<<<<<Output>>>>>>>>>>>
38.9463333333
x =1000000000000000000000000000000.000000, y=1000000000000000000000000000000.000000

Regards,
Kurt

2

KURT PETERS wrote:

I'm trying what I thought was a simple test and getting "bad" results. I am taking some lat long coords, and feeding it into a map. The conversion is not giving "real" values that can be plotted on a map (and actually produces an error when I use annotate).
I'm including the simple code and the output:
  

CODE<<<<<<<<<<<<<<<
                    

import pylab as p
import numpy
from matplotlib.toolkits.basemap import Basemap as Basemap
from matplotlib.colors import rgb2hex
from matplotlib.patches import Polygon

# Lambert Conformal map of lower 48 states.
# create new figure
fig=p.figure()
m1 = Basemap(llcrnrlon=-119,llcrnrlat=22,urcrnrlon=-64,urcrnrlat=49,\
            projection='ortho',lat_1=33,lat_2=45,lon_0=-95,lat_0=40,resolution='c')

#COS
#D + M/60 + S/3600
COSLat=38+56.0/60.0+0.013
COSLon=-1*(104+48.0/60.0)
WASHLat=38+53.0/60.0+23.0/3600.0
WASHLon=-1*(77+32.0/3600.0)

print COSLat
x, y = m1(COSLat,COSLon)
print 'x =%f, y=%f' % (x,y)

m1.plot(,[y],'ko')
ax=p.gca()
ax.annotate('COS1',(COSLat,COSLon))
#ax.annotate('COS2',(x,y))
ax.annotate('Wash1',(WASHLat,WASHLon))
x, y = m1(WASHLat,WASHLon)
#ax.annotate('Wash2',(x,y))

m1.drawcoastlines()
m1.fillcontinents()
m1.drawcountries()
m1.drawstates()
m1.drawparallels(numpy.arange(25,65,4),labels=[1,0,0,0])
m1.drawmeridians(numpy.arange(-120,-40,4),labels=[0,0,0,1])
p.title('full resolution')
p.show()
<<<<<<<<<Output>>>>>>>>>>>
38.9463333333
x =1000000000000000000000000000000.000000, y=1000000000000000000000000000000.000000

Regards,
Kurt

Kurt: If you want the Lambert conformal projection, you should use projection='lcc', not 'ortho'.

Nevertheless, your example works for me if I change the order of the arguments passed to the Basemap instance to

x, y = m1(COSLon,COSLat)

x, y = m1(WASHLon,WASHLat)

Note, longitude goes first.

Also, if you want 'full resolution' coastlines, use resolution='h'.

-Jeff

···

--
Jeffrey S. Whitaker Phone : (303)497-6313
NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449
325 Broadway Boulder, CO, USA 80305-3328

3

OK Jeff, Thanks for your help on the previous question - I had been playing with different projections and resolutions, so that's why the comments didn't match the actual settings in the procedure calls. Now for a "real" problem:

I'm trying to plot the cities from this web site: http://nationalatlas.gov/metadata/citiesx020.faq.html
using that shapefile, which uses points, not polygons (it took a long time to figure out that difference from the example of fillstates.py).
http://nationalatlas.gov/atlasftp.html?openChapters=chpref#chpref

While I think I'm loading everything and displaying everything correctly, the values are not plotting right, nor do they seem realistic.

For instance the point values look like this (which really can't be right):

Shape num Fairbanks, coords=(42082.855349492747, 5336578.2660309337)
Shape num Anchorage, coords=(-442294.67146861833, 5031412.4918638617)

print shp_info - the second value shows to use points not polys:
(35432, 1, [-174.20294189453125, 17.711706161499023, 0.0, 0.0], [178.87460327148437, 71.290138244628906, 0.0, 0.0])
Dictionaries:
['STATE_FIPS', 'NAME', 'POP_2000', 'FEATURE', 'COUNTY', 'STATE', 'FIPS', 'CITIESX020', 'FIPS55', 'DISPLAY', 'POP_RANGE']
STATE_FIPS = 02, NAME = Anchorage, POP_2000=260283, FEATURE = County Seat, COUNTY=Anchorage Borough, STATE=AK, FIPS=02020, CITIESX020 = 194, FIPS55=03000, DISPLAY=0, POP_RANGE=250,000 - 499,999

Here's the code:

···

===============
import pylab as p
import numpy
from matplotlib.toolkits.basemap import Basemap as Basemap
from matplotlib.colors import rgb2hex
from matplotlib.patches import Polygon

# Lambert Conformal map of lower 48 states.
# create new figure
fig=p.figure()
m1 = Basemap(llcrnrlon=-119,llcrnrlat=22,urcrnrlon=-64,urcrnrlat=49,\
            projection='lcc',lat_1=33,lat_2=45,lon_0=-95,resolution='c')
shp_info = m1.readshapefile(r'C:\Python25\Lib\basemap-0.9.9.1\examples\citiesx020','states',drawbounds=True)

ax=p.gca()

#define SHPT_POINT 1 Points
#define SHPT_ARC 3 Arcs (Polylines, possible in parts)
#define SHPT_POLYGON 5 Polygons (possible in parts)
#define SHPT_MULTIPOINT 8 MultiPoint (related points)
print shp_info
print m1.states_info[0].keys()
seqnum={}
criteriatodisplay=[]
ii=0
for shapedict in m1.states_info:
    if int(shapedict['POP_2000'])>100000:
#'STATE_FIPS', 'NAME', 'POP_2000', 'FEATURE', 'COUNTY', 'STATE', 'FIPS', 'CITIESX020', 'FIPS55', 'DISPLAY', 'POP_RANGE']
        print 'STATE_FIPS = %s, NAME = %s, POP_2000=%s, FEATURE = %s, COUNTY=%s, STATE=%s, FIPS=%s, CITIESX020 = %s, FIPS55=%s, DISPLAY=%s, POP_RANGE=%s' %\
        (str(shapedict['STATE_FIPS']), str(shapedict['NAME']), str(shapedict['POP_2000']), str(shapedict['FEATURE']), str(shapedict['COUNTY']), str(shapedict['STATE']), str(shapedict['FIPS']), str(shapedict['CITIESX020']), str(shapedict['FIPS55']), str(shapedict['DISPLAY']), str(shapedict['POP_RANGE']))
        seqnum[shapedict['CITIESX020']]=shapedict['NAME']
        criteriatodisplay.append(shapedict['CITIESX020'])
        ii+=1

print ii

for nshape,seg in enumerate(m1.states):
    if nshape in criteriatodisplay:
        print 'Shape num %s, coords=%s' % (seqnum[nshape], seg)
        h= [seg[0]*0.000278,seg[1]*0.000278]

        ax.annotate(seqnum[nshape],h)
m1.drawcoastlines()
m1.fillcontinents()
m1.drawcountries()
m1.drawstates()
m1.drawparallels(numpy.arange(25,65,4),labels=[1,0,0,0])
m1.drawmeridians(numpy.arange(-120,-40,4),labels=[0,0,0,1])
p.title('Test Cities')
p.show()

Regards,
Kurt

4

And, before someone asks, "Why are you using "h" and this line:
        h= [seg[0]*0.000278,seg[1]*0.000278]
        ax.annotate(seqnum[nshape],h)",
I was using this, instead, but tried to experiment with things to try to make things work right:
        ax.annotate(seqnum[nshape],seg)
.
I usually don't "give up" and post a question unless I've tried a myriad of things, and unfortunately those things sometimes show up in the example code.

Regards,
Kurt

5

KURT PETERS wrote:

OK Jeff, Thanks for your help on the previous question - I had been playing with different projections and resolutions, so that's why the comments didn't match the actual settings in the procedure calls. Now for a "real" problem:

I'm trying to plot the cities from this web site: http://nationalatlas.gov/metadata/citiesx020.faq.html
using that shapefile, which uses points, not polygons (it took a long time to figure out that difference from the example of fillstates.py).
http://nationalatlas.gov/atlasftp.html?openChapters=chpref#chpref

While I think I'm loading everything and displaying everything correctly, the values are not plotting right, nor do they seem realistic.

For instance the point values look like this (which really can't be right):

Shape num Fairbanks, coords=(42082.855349492747, 5336578.2660309337)
Shape num Anchorage, coords=(-442294.67146861833, 5031412.4918638617)

print shp_info - the second value shows to use points not polys:
(35432, 1, [-174.20294189453125, 17.711706161499023, 0.0, 0.0], [178.87460327148437, 71.290138244628906, 0.0, 0.0])
Dictionaries:
['STATE_FIPS', 'NAME', 'POP_2000', 'FEATURE', 'COUNTY', 'STATE', 'FIPS', 'CITIESX020', 'FIPS55', 'DISPLAY', 'POP_RANGE']
STATE_FIPS = 02, NAME = Anchorage, POP_2000=260283, FEATURE = County Seat, COUNTY=Anchorage Borough, STATE=AK, FIPS=02020, CITIESX020 = 194, FIPS55=03000, DISPLAY=0, POP_RANGE=250,000 - 499,999

Here's the code:

import pylab as p
import numpy
from matplotlib.toolkits.basemap import Basemap as Basemap
from matplotlib.colors import rgb2hex
from matplotlib.patches import Polygon

# Lambert Conformal map of lower 48 states.
# create new figure
fig=p.figure()
m1 = Basemap(llcrnrlon=-119,llcrnrlat=22,urcrnrlon=-64,urcrnrlat=49,\
            projection='lcc',lat_1=33,lat_2=45,lon_0=-95,resolution='c')
shp_info = m1.readshapefile(r'C:\Python25\Lib\basemap-0.9.9.1\examples\citiesx020','states',drawbounds=True)

ax=p.gca()

#define SHPT_POINT 1 Points
#define SHPT_ARC 3 Arcs (Polylines, possible in parts)
#define SHPT_POLYGON 5 Polygons (possible in parts)
#define SHPT_MULTIPOINT 8 MultiPoint (related points)
print shp_info
print m1.states_info[0].keys()
seqnum={}
criteriatodisplay=
ii=0
for shapedict in m1.states_info:
    if int(shapedict['POP_2000'])>100000:
#'STATE_FIPS', 'NAME', 'POP_2000', 'FEATURE', 'COUNTY', 'STATE', 'FIPS', 'CITIESX020', 'FIPS55', 'DISPLAY', 'POP_RANGE']
        print 'STATE_FIPS = %s, NAME = %s, POP_2000=%s, FEATURE = %s, COUNTY=%s, STATE=%s, FIPS=%s, CITIESX020 = %s, FIPS55=%s, DISPLAY=%s, POP_RANGE=%s' %\
        (str(shapedict['STATE_FIPS']), str(shapedict['NAME']), str(shapedict['POP_2000']), str(shapedict['FEATURE']), str(shapedict['COUNTY']), str(shapedict['STATE']), str(shapedict['FIPS']), str(shapedict['CITIESX020']), str(shapedict['FIPS55']), str(shapedict['DISPLAY']), str(shapedict['POP_RANGE']))
        seqnum[shapedict['CITIESX020']]=shapedict['NAME']
        criteriatodisplay.append(shapedict['CITIESX020'])
        ii+=1

print ii

for nshape,seg in enumerate(m1.states):
    if nshape in criteriatodisplay:
        print 'Shape num %s, coords=%s' % (seqnum[nshape], seg)
        h= [seg[0]*0.000278,seg[1]*0.000278]

        ax.annotate(seqnum[nshape],h)
m1.drawcoastlines()
m1.fillcontinents()
m1.drawcountries()
m1.drawstates()
m1.drawparallels(numpy.arange(25,65,4),labels=[1,0,0,0])
m1.drawmeridians(numpy.arange(-120,-40,4),labels=[0,0,0,1])
p.title('Test Cities')
p.show()

Regards,
Kurt

Kurt: I had no trouble plotting them with this script:

m = Basemap(llcrnrlon=-119,llcrnrlat=22,urcrnrlon=-64,urcrnrlat=49,\
             projection='lcc',lat_1=33,lat_2=45,lon_0=-95,resolution='c')
shp_info = m.readshapefile('citiesx020','cities')
x, y = zip(*m.cities)
m.drawcoastlines()
m.drawcountries()
m.fillcontinents()
m.scatter(x,y,2,'b',marker='o',faceted=False,zorder=10)
p.show()

This is adapted from the plotcities.py example, which was designed for point files (fillstates.py was designed for polygon files). In this case, m.cities is just a list of x,y coordinates. I don't know why ax.annotate wasn't working for you.

I know the shapefile stuff is non-intuitive and could use a lot of work. Perhaps when you can offer some suggestions for the docs, or for re-designing the interface.

-Jeff

···

--
Jeffrey S. Whitaker Phone : (303)497-6313
NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449
325 Broadway Boulder, CO, USA 80305-3328