APPEND

If APPEND is specified, then a new data set is created, containing the result and n1 is unchanged.

AVERAGE

This option will not work for the SUBTRACT command. If AVERAGE is specified, the data is averaged together according to the Y statistics. If Y is non zero but DY is 0 then DY is assumed to be 1. If both Y1 and DY1 are zero then Y3,DY3 = Y2,DY2. Y3=(Y1/DY1**2+Y2/DY2**2)/(1/DY1**2+1/DY2**2) DY3=SQRT(2*DY1**2*DY2**2/(DY1**2+DY2**2)) If you wish to average several data sets with statistics, this should give you the correct result. Zero data with zero statistics indicates the absence of data. If you wish to average several data sets without statistics then you should always set the statistics to a "reasonable" value.

CHECK

CHECK=OFF turns off data set checking. When CHECK=ON both data sets must have identical X (and Y if mesh) values, but data set n2 may contain more points than n1. If (DX/DY) is non zero then the both DX and X must be identical within 1% of DX. If you have data sets with non identical values of X you may create a set with identical values using the BIN command. you may also add together data sets with the BIN command. If the X values of 2 data sets are not quite identical. You may force TOPDRAWER to add them by setting DX for the data 100 times greater than the difference in X or by setting CHECK=OFF.

ERROR

ERROR=OFF excludes the errors from the FIT in the computation. (Default:ERROR=ON)

FIT

Specifies that the last FIT is to be added or subtracted from the data set. See:Command FIT.

LIMITED

You may specify the limits over which the histograms are to be added. If you specify the Y or Z limits, then all data that contains values inside these limits will be added. For example if you ADD 1 to 2 LIMITED FROM Y=10 to Y=11 But data set 1 contains the followind data: 1,0; 2,10; 3,0; 4,11; 5,0 Points 2 to 4 inclusive will be added, and only points 1 and 5 will be omitted.

LOG

If LOG is specified then the result of the command is typed on your terminal.

VECTOR

The DX,DY,DZ's will be added together assuming they are a vector. The X,Y,Z are not changed, and they should match for both input data sets.

If POLAR or SPHERICAL are ON the coordinates are handled correctly.

WEIGHT-EWEIGHT

WEIGHT=n specifies a weighting factor to multiply the data by before adding or subtracting it. EWEIGHT=n specifies the error on WEIGHT. This option must precede the data set number.

X|Y

Selects which coordinate of regular data is to be added. Mesh data always adds the dependent coordinate which is usually z. (Default:Y)

notes

For mesh data the independent coordinate must be Z. For 2-d data the independent coordinate is always Y. If you add normal data to mesh data each normal Y value is added to the corresponding mesh Z value. You may not add mesh data to normal 2-d data.

If EFFICIENCY is not specified then the new value is Y3=Y1(+-)Y2. The errors (DY) are treated as if the data sets are uncorrelated DY3=SQRT(DY1**2+DY2**2).

The ADD command with CHECK=OFF allows you to combine X,Y,Z... data TD:SWAP X Y SET=1 from 1 data set with mismatched data from another set. For example you wish to plot Y of set 1 vs Y of set 2. TD:SWAP X Y SET=1 TD:ADD 1,1 APPEND (Produces set 3=set 1) TD:Y=0 SET=LAST (Set 3 has only X) TD:ADD 2,3 CHECK=OFF (Set 3 has Y(1),Y(2)) Set 3 now has X=Y(set 1) and Y=Y(set 2)

example

TD:ADD 1 TO 2 or... TD:ADD 2 1 or... TD:ADD TO 2 1 Data set 1 is added to data set 2. Data set 1 is unchanged. TD:ADD 1 TO 2 APPEND Data set 1 and 2 are added. The result in put into a new data set. Both sets 1 and 2 are unchanged. TD:SUBTRACT 1 FROM 2 Data set 1 is subtracted from data set 2. Data set 1 is unchanged. See:Command DIVIDE,MULTIPLY