3.1.9 Error handling

There are 2 variables which indicate the warnings/errors presence during plot creation. Normally user should set it to zero by SetWarn(0); before plotting and check if WarnCode is not zero after plotting. Only last warning will be saved. All warnings/errors produced by MathGL is not critical – the plot just will not be drawn.

Method on mglGraph (C++): void SetWarn (int code, const char *who="")

Set warning code and corresponding message from function who. Normally you should call this function only for clearing the warning state, i.e. call SetWarn(0);.

General option (C++) of mglGraph: char * Message

Pointer to buffer for writing messages about matters why some plot are not drawn. Set to NULL to disable messages. The buffer length must be at least 1024. If Message[0]==0 then there are no messages

Method on mglGraph (C++, Python): int GetWarnCode ()

C function: int mgl_get_warn_code (HMGL gr)

Return the numerical ID of warning about the not drawn plot. Possible values are:

mglWarnNone=0

Everything OK

mglWarnDim

Data dimension(s) is incompatible

mglWarnLow

Data dimension(s) is too small

mglWarnNeg

Minimal data value is negative

mglWarnFile

No file or wrong data dimensions

mglWarnMem

Not enough memory

mglWarnZero

Data values are zero

mglWarnLegA

Too many legend entries

mglWarnLeg

No legend entries

mglWarnSlc

Slice value is out of range

mglWarnCnt

Number of contours is zero or negative

mglWarnOpen

Couldn’t open file

mglWarnLId

Light: ID is out of range

mglWarnSize

Setsize: size(s) is zero or negative

mglWarnFmt

Format is not supported for that build

Obsolete option of mglGraph: int WarnCode

Numerical ID of warning about the not drawn plot.