Printing

Printing#

MatX allows printing of any operator or tensor for debugging. If the operator is not backed by memory MatX will fetch all values based on the size and rank. If the operator is a tensor, MatX can determine whether the memory is on the host or device and print the tensor appropriately. The print function takes an operator as the first parameter, and optionally the number of elements to print in each dimension. The value of 0 is a special placeholder for “all”, and using it prints all values in that dimension.

To print a tensor or operator:

auto t = make_tensor<TypeParam>({3});
(t = ones(t.Shape())).run();
print(t);

In this case MatX is fetching the data from the device and printing it to the screen. However, storing in a tensor is optional. The following code gives the same result:

auto t = make_tensor<TypeParam>({3});
print(ones(t.Shape()));

By just printing the operator, MatX can materialize the data without going to device memory

To print only two elements:

auto t = make_tensor<TypeParam>({3});
print(ones(t.Shape()), 2);

For a multi-dimension operator, the following code prints only the first element in the first dimension, every element in the second dimension, and 10 elements in the last dimension.

auto t = make_tensor<TypeParam>({3, 10, 20});
print(ones(t.Shape()), 1, 0, 10);

To print just the shape and type of an operator, use print_shape:

auto t = make_tensor<TypeParam>({3, 10, 20});
print_shape(ones(t.Shape()), 1, 0, 10);