Scatter plot of two rasters

[ShouvikJha]

Xander Bakker‌ and Dan Patterson‌ , Kindly your cooperation is highly appreciate. 

I have two raster file, i want to perform Scatter plot of those raster . I found one code that is written by Dan Patterson‌ 

Below code

from matplotlib import pyplot as plt
xs = [1,3,2,5,6,4] # Which fomart of data i have to give here?
ys = [3,2,1,5,3,2]
plt.scatter(xs, ys)
main_title ="My first graph"
plt.title(main_title, loc='center')  #loc is either left, right or center
plt.minorticks_on()
plt.tick_params(which='major', direction='in', length=6, width=2)
plt.tick_params(which='minor', direction='in', length=4, width=2)
plt.show()‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Earlier Dan suggest to someone convert those raster to arrays. I followed the same  but could not solve it. How to process tiff to array.

 how do i execute two raster in X and Y axis. I have tiff images.

Branched from Perform Raster Calculation from Multiple Sub-folder Using ArcPy 

[DanPatterson_Retired]

you have to plot them separately as rasters not as a scatter plot, you can convert a raster to rows and columns and plot those as a scatterplot, so I am not sure what you want to do specifically.  What does your data look like now?

[NeilAyres]

I would normally not do this on the entire raster or rasters but create a random subset of them using Create Random points and then use Sample.

Then just use the graphing tools inside ArcMap.

[ShouvikJha]

Dan Patterson‌ 

Thank you. I want to do  on  cell by cell basis. I have two different parameters of raster data, so one parameter i want to plot  in X axis and another one Y axis to make it relation between two parameters. 

How do i convert it in row and column  format. can i convert it in  ASCII format? 

Data is tiff format same as which we got from our above scrip suggested by xander_bakker‌

[ShouvikJha]

Reply from Dan Patterson‌

before you go off into a side tangent of graphing and trying to 'correlate', 'predict' or extrapolate see...

 Geographically Weighted Regression (GWR)—Help | ArcGIS for Desktop 

Only if you are working with interval/ratio and there is some real predictive behaviour between the two variables.  Looking for correlations, relationships between two variables via a magical statistical test is overused.  But if you are looking for an association then the above and other substitutes will save a flurry of activity in the wrong direction

For nominal data...  Combine—Help | ArcGIS for Desktop   gives you the basis for tests of Association such as the chi-squared test.  And at worst it gives you a tabular output for discussion

Make your intent clear and specific... otherwise people with keep throwing suggestions out that will meet vague goals ... not necessary specific ones.

[ShouvikJha]

Thank you. I am not getting your points. i am trying plot two variable of raster like this ... 

[ShouvikJha]

Reply from Dan Patterson‌

If the rasters aren't huge convert to points, then Ordinary Least Squares (OLS)—Help | ArcGIS for Desktop I think the report allows for a graph

[ShouvikJha]

Xander Bakker‌, Dan Patterson‌ , I moved total conversion from there to here. Please cooperate with us. Sorry for the inconvenience cause.  

[ShouvikJha]

Dan Patterson‌, As your last comment we have huge data point. number of columns and rows 2737, 2025 respectively. So whats is  the best way to plot those raster. 

[XanderBakker]

I think the suggestion by Neil Ayres is an option you should look at. Use  Create Random Points—Help | ArcGIS for Desktop , followed by Extract Multi Values to Points—Help | ArcGIS for Desktop to graph the two variables (rasters) together in a scatter plot. 

The alternative is using numpy to access the pixel values and create a resulting table with the combination of the values for each cell. In your case that would be over 5.5 M records, which might yield errors.