I' ve imported SPSS data via the DBF format into Origin. Unfortunalety,
SPSS system missing values are convereted into zeros (0). While calculating
statistics on the data, Origin uses the 0s as valid data - logical.

Question: Is there any possibility to define MISSING VALUES in Origin?

Thanks for Your time.

Regards

When spreadsheet programs first appeared on computers it was recognized that there was a need for a special number that was Not-A-Number which would - when used in a calculation - generate itself. This value went by several shorthand notations including NAN and NANUM. Origin has such a number and its internal value is -1.23456789E-300. Since this value is out of the range of numeric assignment (1E-128 to 1E+127) we need a way to enter this in worksheets and use it in calculations.
The Origin worksheet displays missing values as "--", but don't confuse this display (output) with what you enter as a missing value (input). If a worksheet column is type numeric, then entering any text:

•"silly" •"--" •"oops"

I do not exaxtly know you mean by "defining",values

•if you just want to replace "0" by missing value after importing your data, the answer is simple: you just highlight all cells which contain "0" and type "--"
(two minus signs) to replace its values. As you will know, you can do this with whole rows or columns with the simple command edit: clear.

•if this seems very time consuming to you, it is possible to use set column or Labtalk Scripts. Of course this only works if your data will not contain deliberately set values of zero. Most simple is a set columns command :
set columns.....
col(A)= (col(A)==0) ? silly : col(A)
A (B, C, D , Ei, Blut, Kakao) is the name of the column
this is a simple if then sequence. It checks if a value in the columns is 0. If no it replaces the actual value with the actual value (i.e. does nothing), if yes it replaces 0 with the value of the variable "silly". As you did not set a value to this variable, it has the value "--" .(!?). In other words what you do is cheating Origin with its own bugs. ;->

•if you want to set this as a option during import (which is what I would name as definining), I don't know how to do this, but I think this will not work.

Hope this helps, Peter