forestatrisk.misc package

forestatrisk.misc.countpix module

countpix(input_raster, value=1, blk_rows=0)

Count the number of pixels having a specific value.

Count the number of pixels (and the corresponding area in ha) having a specific value.

Parameters:

• input_raster – Input raster file.

• value – Target value.

• blk_rows – if > 0, number of lines per block.

Returns:

A dictionary with the number of pixels having the specified value (npix) and the total area (area, in ha).

forestatrisk.misc.miscellaneous module

invlogit(x)

Compute the inverse-logit of a numpy array.

We differenciate the positive and negative values to avoid under/overflow with the use of exp().

Parameters:

x – Numpy array.

Returns:

Return the inverse-logit of the array.

make_dir(newdir)

Make new directory

• Already exists, silently complete

• Regular file in the way, raise an exception

• Parent directory(ies) does not exist, make them as well

Parameters:

newdir – Directory path to create.

make_square(rasterfile, square_size=33)

Compute square information.

This function computes block information from the caracteristics of a raster file and an indication on the number of rows to consider.

Parameters:

• rasterfile – Path to a raster file.

• square_size – Pixel number to define square side size.

Returns:

A tuple of length 6 including square number, square number on x axis, square number on y axis, square offsets on x axis, square offsets on y axis, square sizes on x axis, square sizes on y axis.

makeblock(rasterfile, blk_rows=128)

Compute block information.

This function computes block information from the caracteristics of a raster file and an indication on the number of rows to consider.

Parameters:

• rasterfile – Path to a raster file.

• blk_rows – If > 0, number of rows for block. If <=0, the block size will be 256 x 256.

Returns:

A tuple of length 6 including block number, block number on x axis, block number on y axis, block offsets on x axis, block offsets on y axis, block sizes on x axis, block sizes on y axis.

progress_bar(niter, i)

Draw progress_bar

Parameters:

• niter – Total number of iterations.

• i – Current number of iteration (starts at 1).

rescale(value)

Rescale probability values to 1-65535.

This function rescales probability values (float in [0, 1]) to integer values in [1, 65535]. Raster data can then be of type UInt16 with 0 as nodata value.

Parameters:

value – Numpy array of float values in [0, 1].

Returns:

Rescaled numpy array of integer values in [1, 65535].