Refs #9790 Updated documentation

Code/Mantid/docs/source/algorithms/EnginXFitPeaks-v1.rst

@@ -14,14 +14,14 @@ Description
    This algorithm is being developed for a specific instrument. It might get changed or even 
    removed without a notification, should instrument scientists decide to do so.
 
-The pattern is specified by providing a list of dSpacing values where Bragg peaks are expected. Assuming Guassian shape, the algorithm then fits peaks in those areas. The dSpacing values for ExpectedPeaks are then converted by
-"""
-dSpacingToTof = lambda d: 252.816 * 2 * (50 + detL2) * math.sin(detTwoTheta / 2.0) * d
-"""
+
+The pattern is specified by providing a list of dSpacing values where Bragg peaks are expected. The algorithm then fits peaks in those areas using a peak fitting function. The dSpacing values for ExpectedPeaks are then converted by Mantid's convertUnits function to TOF.
+
 These values are used as start peak position in fit. It is these adjusted peak TOF value positions that are fitted against ExpectedPeaks dSpacing values according to:
-"""
-TOF = DifC*d + Zero.
-"""
+
+
+.. math:: TOF = DifC*d + Zero
+
 
 ZERO and Difc can then be used within the GSAS program.