# Synopsis

PDX_MSGT gdx_CurveGetLength(long option, MDA_PTR gdx_curv_ptr, double t0, double t1, double pc_error, double *length)

# Purpose

Compute arc length of a curve or curve segment

# Description

This function computes the arc length of a curve or of a curve segment.

# Input

## option

Not used.

## gdx_curv_ptr

The GDX curve.

## t0

Start parameter value (not normalized)

## t1

End parameter value (not normalized). If the curve is closed, then t1 may be less than t0, in which case the sum of the lengths of the segments [t1,tmax] and [tmin,t0] will be computed.

## pc_error

Allowable per cent error in the computed arc length. Example: if the true arc length is 100, and pc_error = 1, then the computed arc length should be between 99 and 101.

# Output

## length

The computed arc length.

# Return

          GDX_NOERR
          GDX_BADSUBPARMS
          Low level error return
          .fi