gdaDStat#

Purpose#

Computes descriptive statistics on multiple Nx1 variables in a GAUSS Data Archive.

Format#

dout = gdaDStat(dc0, filename, vnamevar)#
Parameters:

  • dc0 (struct) –

    an instance of a dstatmtControl structure with the following members:

    dc0.altnames

    Kx1 string array of alternate variable names for the output. Default = ""

    dc0.maxbytes

    scalar, the maximum number of bytes to be read per iteration of the read loop. Default = 1e9.

    dc0.maxvec

    scalar, the largest number of elements allowed in any one matrix. Default = 20000.

    dc0.miss

    scalar, one of the following:

    0:

    There are no missing values (fastest).

    1:

    Listwise deletion, drop a row if any missings occur in it.

    2:

    Pairwise deletion.

    Default = 0.

    dc0.output

    scalar, one of the following:

    0:

    Do not print output table.

    1:

    Print output table.

    Default = 1.

    dc0.row

    scalar, the number of rows of vnamevar to be read per iteration of the read loop. If 0, (default) the number of rows will be calculated using dc0.maxbytes and dc0.maxvec.

  • filename (string) – name of data file.

  • vnamevar (Kx1 string array or Kx1 vector) – names of variables or indices of variables.

Returns:

dout (struct) –

instance of dstatmtOut struct with the following members:

dout.vnames

Kx1 string array, the names of the variables used in the statistics.

dout.mean

Kx1 vector, means.

dout.var

Kx1 vector, variance.

dout.std

Kx1 vector, standard deviation.

dout.min

Kx1 vector, minima.

dout.max

Kx1 vector, maxima.

dout.valid

Kx1 vector, the number of valid cases.

dout.missing

Kx1 vector, the number of missing cases.

dout.errcode

scalar, error code, 0 if successful, or one of the following:

1:

No GDA indicated.

4:

Not implemented for complex data.

5:

Variable must be type matrix.

6:

Too many variables specified.

7:

Too many missings - no data left after packing.

8:

Name variable wrong size.

9:

altnames member of dstatmtControl structure wrong size.

11:

Data read error.

Examples#

// Declare instance of dstatmtControl
struct dstatmtControl dc0;

// Set structure to default values
dc0 = dstatmtControlCreate();

// Declare instance of dstatmtOut
struct dstatmtOut dout;

// Indices of variables to be evaluated
vars = { 1, 4, 5, 8 };

// Call gdaDStat
dout = gdaDStat(dc0, "myfile.gda", vars);

This example computes descriptive statistics on the first, fourth, fifth and eighth variables in myfile.gda.

Remarks#

The variables referenced by vnamevar must all be Nx1.

The names of the variables in the GDA will be used for the output by default. To use alternate names, set the altnames member of the dstatmtControl structure.

If pairwise deletion is used, the minima and maxima will be the true values for the valid data. The means and standard deviations will be computed using the correct number of valid observations for each variable.

Source#

gdadstat.src

See also

Functions gdaDStatMat(), dstatmtControlCreate()

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