Drawing shaded area depending on distance with latitude and altitude coordinate

Mark Lawrence breamoreboy at yahoo.co.uk
Mon Jan 6 15:16:53 EST 2014


On 06/01/2014 20:08, Isaac Won wrote:
> I have tried to make a plot of points with longitude and latitude coordinate, and draw shaded area with distance from one point. So, I thought that I could uae contourf function from matplotlibrary. My code is:
>      import haversine
>      import numpy as np
>      import matplotlib.pyplot as plt
>      with open(filin, 'r') as f:
>      arrays = [map(float, line.split()) for line in f]
>          newa = [[x[1],-x[2]] for x in arrays]
>
>      lat = np.zeros(275)
>      lon = np.zeros(275)
>      for c in range(0,275):
>          lat[c] = newa[c][0]
>          lon[c] = newa[c][1]
>
>      with open(filin, 'r') as f:
>          arrays = [map(float, line.split()) for line in f]
>      newa = [[x[1],-x[2]] for x in arrays]
>
>      lat = np.zeros(275)
>      lon = np.zeros(275)
>      for c in range(0,275):
>          lat[c] = newa[c][0]
>          lon[c] = newa[c][1]
>
>
>      dis = np.zeros(275)
>
>      for c in range(0,275):
>          dis[c] = haversine.distance(newa[0],[lat[c],lon[c]])
>
>      dis1 = [[]]*1
>
>      for c in range(0,275):
>          dis1[0].append(dis[c])
>
>
>      cs = plt.contourf(lon,lat,dis1)
>      cb = plt.colorbar(cs)
>
>      plt.plot(-lon[0],lat[0],'ro')
>      plt.plot(-lon[275],lat[275],'ko')
>      plt.plot(-lon[1:275],lat[1:275],'bo')
>      plt.xlabel('Longitude(West)')
>      plt.ylabel('Latitude(North)')
>      plt.gca().invert_xaxis()
>      plt.show()
>
> My idea in this code was that I could made a shaded contour by distance from a certain point which was noted as newa[0] in the code. I calculated distances between newa[0] and other points by haversine module which calculate distances with longitudes and latitudes of two points. However, whenever I ran this code, I got the error related to X, Y or Z in contourf such as:
>      TypeError: Length of x must be number of columns in z, and length of y must be number of rows.
>
> IF I use meshgrid for X and Y, I also get:
>      TypeError: Inputs x and y must be 1D or 2D.
>
> I just need to draw shaded contour with distance from one point on the top of the plot of each point.
>
> If you give any idea or hint, I will really apprecite. Thank you, Isaac
>

Sorry I can't help directly but can point you here 
https://lists.sourceforge.net/lists/listinfo/matplotlib-users or perhaps 
stackoverflow.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask 
what you can do for our language.

Mark Lawrence




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