Assert that a Computed Output Size is Positive

Rejects a computed output size that no tensor can have, i.e. one that is not a positive number. Operators such as convolutions and pooling compute their spatial output sizes from kernel_size, stride, padding and dilation, a combination of which can produce a size of zero or less. Unknown (NA) sizes are accepted, since nothing can be said about them.

Usage

assert_positive_extent(extent, shape_in, id)

Arguments

extent

(numeric())
The sizes an operator computed for the dimensions it changes, e.g. the spatial dimensions of a convolution.

shape_in

(integer())
The input shape, used for the error message.

id

(character(1) | NULL)
The id of the PipeOp, which the error message names. NULL when the assertion is not made for a PipeOp.

Value

The extent, invisibly.

See also

Other Shape Assertions: assert_dim_in_range(), assert_known_dims(), assert_ndim(), assert_not_batch_dim(), assert_same_batch_size(), assert_same_ndim(), assert_shape(), assert_shapes()

Examples

assert_positive_extent(c(30, NA), c(NA, 3, 32, 32), id = "nn_conv2d")
try(assert_positive_extent(c(0, 4), c(NA, 3, 32, 32), id = "nn_conv2d"))
#> Error : PipeOp 'nn_conv2d' cannot be applied to the input shape (NA,3,32,32): it would produce an output of size 0, 4, which no tensor can have. Check 'kernel_size', 'stride', 'padding' and 'dilation'.