In earthquake data analysis, it is often necessary to stack arrays to create a new array that combines data from multiple sources. For example, we might want to stack arrays of earthquake locations, magnitudes, and depths to create a single array that contains all of this information.
In dask, we can use the da.stack() function to stack multiple dask arrays along a new axis. The function takes a sequence of dask arrays as input and returns a new dask array that has one more dimension than the input arrays.
Here's an example of how to stack latitude, longitude, and depth arrays to create a new array of earthquake locations:
import dask.array as dawith h5py.File('earthquake_data.h5', 'r') as f: latitude = da.from_array(f['latitude'], chunks='auto') longitude = da.from_array(f['longitude'], chunks='auto') depth = da.from_array(f['depth'], chunks='auto')locations = da.stack([latitude, longitude, depth], axis=-1) |
In this example, we use da.from_array() to create dask arrays from the latitude, longitude, and depth datasets in the HDF5 file. We pass chunks='auto' to let dask determine the optimal chunk size based on the size of the data.
We then use da.stack() to stack the latitude, longitude, and depth arrays along a new axis. We pass axis=-1 to stack the arrays along the last axis, which creates a new axis for the earthquake locations.
We can also stack arrays of different shapes, as long as they have compatible dimensions. For example, we can stack arrays of earthquake locations and magnitudes to create a new array that contains both:
import dask.array as dawith h5py.File('earthquake_data.h5', 'r') as f: latitude = da.from_array(f['latitude'], chunks='auto') longitude = da.from_array(f['longitude'], chunks='auto') magnitude = da.from_array(f['magnitude'], chunks='auto')locations = da.stack([latitude, longitude], axis=-1)earthquakes = da.stack([locations, magnitude], axis=-1) |
In this example, we use da.stack() to stack the latitude and longitude arrays along a new axis to create a locations array. We then stack the locations array and the magnitude array along a new axis to create an earthquakes array that contains both the earthquake locations and magnitudes.