distance

Herror ::distance_pl ( const HTuple &Row, const HTuple &Column, const HTuple &Row1, const HTuple &Column1, const HTuple &Row2, const HTuple &Column2, double *Distance ) Herror ::distance_pl ( const HTuple &Row, const HTuple &Column, const HTuple &Row1, const HTuple &Column1, const HTuple &Row2, const HTuple &Column2, HTuple *Distance )

Calculate the distance between one point and one line.

The operator ::distance_pl calculates the orthogonal distance between a point (Row,Column) and a line, given by two arbitrary points of the line. The result is passed in Distance.

Parameters

`Row` (input_control)	point.y(-array) `->` HTuple.double / long
Row of the point.

`Column` (input_control)	point.x(-array) `->` HTuple.double / long
Column of the point.

`Row1` (input_control)	point.y(-array) `->` HTuple.double / long
Row of the first point of the line.

`Column1` (input_control)	point.x(-array) `->` HTuple.double / long
Column of the first point of the line.

`Row2` (input_control)	point.y(-array) `->` HTuple.double / long
Row of the second point of the line.

`Column2` (input_control)	point.x(-array) `->` HTuple.double / long
Column of the second point of the line.

`Distance` (output_control)	number(-array) `->` (HTuple.) double *
Distance between the points

Example

read_image (Image, 'mreut')
dev_open_window (0, 0, 512, 512, 'white', WindowHandle)
dev_display (Image)
dev_set_color ('black')
threshold (Image, Region, 180, 255)
dev_clear_window ()
dev_display (Region)
connection (Region, ConnectedRegions)
select_shape (ConnectedRegions, SelectedRegions, 'area', 'and',
              10000, 100000000)
get_region_contour (SelectedRegions, Rows, Columns)
RowLine1 := 5
ColLine1 := 300
RowLine2 := 300
ColLine2 := 400
NumberTuple := |Rows|
dev_set_color ('red')
disp_line (WindowHandle, RowLine1, ColLine1, RowLine2, ColLine2)
dev_set_color ('green')
for i := 1 to NumberTuple by 5
  disp_line (WindowHandle, Rows[i], Columns[i]-2, Rows[i], Columns[i]+2)
  disp_line (WindowHandle, Rows[i]-2, Columns[i], Rows[i]+2, Columns[i])
  distance_pl (Rows[i], Columns[i], RowLine1, ColLine1,
               RowLine2, ColLine2, Distance)
endfor

Result

::distance_pl returns H_MSG_TRUE.

Alternatives

::distance_ps

See also

::distance_pp, ::distance_pr

Module

Basic operators