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@yanofsky yanofsky/Makefile
Last active Aug 29, 2015

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Turning GSHAP data into a geoImage

Data GSHAP data to image

This is the data downloading and cleaing parts of the map making process described in this blog post.

to run, open your terminal

$ make

#!/usr/bin/env python
# encoding: utf-8
import Image
def main():
#open the data file
with open("GSHPUB.DAT") as f:
data = f.read().split("\r\n")
data = map(lambda x: x.split("\t"), data)
#define the dimenstions of the image
#one degree for each 1/10th of a degree
width = 180*2*10
height = 90*2*10
#create a new image object
img = Image.new("RGB",[width+1,height+1])
pixels = img.load()
#loop through the data
for d in data:
try:
#shift the data to be all positive numbers
x = int(float(d[0])*10) + (180*10)
y = height - (int(float(d[1])*10) + (90*10))
#set no data to 0
c = int(float(d[2])*10) if d[2] != "NaN" else 0
#if the data is set too far east...wrap it to the west
if x > width:
x = x - width
#assign the data and check for errors
try:
pixels[x,y] = (c,c,c)
except IndexError:
print "Error with: ", x,y,c
except ValueError:
print "Error with: ", d
#save the image
img.save("output.tiff", "TIFF")
pass
if __name__ == '__main__':
main()
DATA_FILE = ./GSHPUB.DAT
DATA_ZIP = ./gshpub.zip
DATA_ZIP_LOCATION = http://www.seismo.ethz.ch/static/gshap/gshpub.zip
IMAGE_SCRIPT = ./create_earthquake_raster.py
OUTPUT_IMAGE = ./output.tiff
all: ${OUTPUT_IMAGE}
${OUTPUT_IMAGE}: ${IMAGE_SCRIPT} ${DATA_FILE}
@echo creating image file
python ${IMAGE_SCRIPT}
${DATA_FILE}: ${DATA_ZIP}
@echo unzipping data file
unzip -o ${DATA_ZIP}
${DATA_ZIP}:
@echo downloading data file
curl ${DATA_ZIP_LOCATION} -O -L
clean:
rm ${DATA_FILE}
rm ${OUTPUT_IMAGE}
rm ${DATA_ZIP}
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