assign.md

assign

Prototype

template<class RasterTo, class RasterFrom>
void assign(RasterTo& to, const RasterFrom& from);

Description

Assigns the value of each element in Raster from to the corresponding element in Raster to

Definition

<pronto/raster/assign.h> (open in Github)

Requirements on types

The value_type of RasterFrom must be castable to the value_type of RasterTo. RasterTo must be mutable. RasterFrom and RasterTo both must be Rasters.

Preconditions

to and from must have the same dimensions

Complexity

The complexity is the cost of iterating over all elements in to and from. It is at least O(n) where n is the number of cells but can be more depending on the type of from and to.

Example of use

//example_assign.cpp

#include <pronto/raster/assign.h>
#include <pronto/raster/io.h>
#include <pronto/raster/plot_raster.h>

namespace pr = pronto::raster;

int main()
{
  auto a = pr::create_temp<int>(3, 4, GDT_Byte);
  auto b = pr::create_temp<int>(3, 4, GDT_Byte);
  int count = 0;
  for (auto&& i : a) {
    i = count++;
  }

  // copies the values in a over to b
  pr::assign(b, a);

  for (auto&& i : a) {
    i = count++;
  }

  plot_raster(a);
  plot_raster(b);
}

Output:

Rows: 3, Cols: 4, Value type: int
12      13      14      15
16      17      18      19
20      21      22      23

Rows: 3, Cols: 4, Value type: int
0       1       2       3
4       5       6       7
8       9       10      11

Notes

See also