# PGPLOT Module: PGCONB -- contour map of a 2D data array, with blanking

SUBROUTINE PGCONB (A, IDIM, JDIM, I1, I2, J1, J2, C, NC, TR,

1 BLANK)

INTEGER IDIM, JDIM, I1, I2, J1, J2, NC

REAL A(IDIM,JDIM), C(*), TR(6), BLANK

Draw a contour map of an array. This routine is the same as PGCONS,

except that array elements that have the "magic value" defined by

argument BLANK are ignored, making gaps in the contour map. The

routine may be useful for data measured on most but not all of the

points of a grid.

**Arguments**

A (input) : data array.

IDIM (input) : first dimension of A.

JDIM (input) : second dimension of A.

I1,I2 (input) : range of first index to be contoured (inclusive).

J1,J2 (input) : range of second index to be contoured (inclusive).

C (input) : array of contour levels (in the same units as the

data in array A); dimension at least NC.

NC (input) : number of contour levels (less than or equal to

dimension of C). The absolute value of this

argument is used (for compatibility with PGCONT,

where the sign of NC is significant).

TR (input) : array defining a transformation between the I,J

grid of the array and the world coordinates. The

world coordinates of the array point A(I,J) are

given by:

X = TR(1) + TR(2)*I + TR(3)*J

Y = TR(4) + TR(5)*I + TR(6)*J

Usually TR(3) and TR(5) are zero - unless the

coordinate transformation involves a rotation

or shear.

BLANK (input) : elements of array A that are exactly equal to

this value are ignored (blanked).