I have created profiles at multiple locations with lines.

Now I want to add points to that graph, how do I do that?

Here is the script:

import arcpy
import os
import matplotlib.pyplot as plt
import numpy

#settings for datasources
linesPath = "lines"
rasterPath = "raster"
pointsPath = "points"

# settings for output profiles PNG's
profileFolder = r"\test_arcpy\profile"
profilePrefix = "ArcPy_"
profilePostfix = "_new.png"
fldName = "profile_na"

# standard NoData mapping
NoDataValue = -9999

# describe raster
inDesc = arcpy.Describe(rasterPath)
rasMeanCellHeight = inDesc.MeanCellHeight
rasMeanCellWidth = inDesc.MeanCellWidth

# search cursor
fldShape = "SHAPE@"
flds = [fldShape, fldName]
with arcpy.da.SearchCursor(linesPath, flds) as curs:
    for row in curs:
        feat = row[0]
        profileName = row[1]

        # read extent of feature and create point for lower left corner
        extent = feat.extent
        print "Processing: {0}".format(profileName)
        pntLL = arcpy.Point(extent.XMin, extent.YMin)

        # determine number of rows and cols to extract from raster for this feature
        width = extent.width
        height = extent.height
        cols = int(width / rasMeanCellWidth)
        rows = int(height / rasMeanCellHeight)

        # create Numpy array for extent of feature
        arrNP = arcpy.RasterToNumPyArray(rasterPath, pntLL, cols, rows, NoDataValue)

        # create empty arrays for distance (d) and altitude (z) and NAP line (zv)
        d = []
        z = []
        zv = []

        # loop through polyline and extract a point each meter
        for dist in range(0, int(feat.getLength("PLANAR"))):
            XYpointGeom = feat.positionAlongLine(dist, False)
            XYpoint = XYpointGeom.firstPoint

            # translate XYpoint to  row, col (needs additional checking)
            c = int((XYpoint.X - pntLL.X) / rasMeanCellWidth)
            r2 = int((XYpoint.Y - pntLL.Y) / rasMeanCellHeight)
            r = rows - r2
            if c >= cols:
                c = cols-1
            if r >= rows:
                r = rows-1

            # extract value from raster and handle NoData
            zVal = arrNP[r,c]
            if not zVal == NoDataValue:

        # define output profile filename and figure size settings
        elevPNG = profileFolder + os.sep + profilePrefix + profileName + profilePostfix
        fig = plt.figure(figsize=(10, 3.5)) # inches

        # plot profile, define styles
        plt.plot(d,z,'ro',alpha=0.3, markersize=3)
        plt.xlabel('Distance from start')
        plt.title('Profile {0} using Python matplotlib'.format(profileName))

        # change font size
        plt.rcParams.update({'font.size': 8})

        # save graph as PNG
        fig.savefig(elevPNG, dpi=300)

# delete some objects
del arrNP, XYpointGeom, XYpoint
print "PNGs stored in: {0}".format(profileFolder)

enter image description here

closed as unclear what you're asking by PolyGeo Aug 2 at 13:05

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • At the moment it looks like you are presenting a lot of code, with little description, and asking us to improve it. I suspect that is why no potential answerers have volunteered their time to try and answer it. – PolyGeo Aug 2 at 13:07

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