loadd¶

Purpose¶

Loads data from a dataset. The supported dataset types are CSV, Excel (xlsx, xlsx), HDF5, GAUSS Matrix (fmt), GAUSS Dataset (dat), Stata (dta), and SAS (sas7bdat, sas7bcat). Existing dataframes are also supported.

Format¶

y = loadd(dataset[, varnames])¶

Parameters

dataset (string or existing dataframe) –
filepath to the dataset on disk, URL, or existing dataframe.

If the a URL is provided (with http or https schema), the dataset will be downloaded first. Since libcurl is used for all web operations, various proxy settings can be set using the relevant libcurl environment variables (see https://curl.haxx.se/libcurl/c/CURLOPT_PROXY.html).
varnames (string) –
Formula string indicating which variable names to load from the dataset

E.g ".", include all variables;

E.g "Income + Limit ", include "Income" and "Limit";

E.g ". - Cards", include all variables except for "Cards".

Returns

y (NxK matrix) – data.

Examples¶

Load all contents of a GAUSS dataset¶

// Create file name with full path
file = getGAUSShome() $+ "examples/credit.dat";

// Load all rows from all columns of the dataset
y = loadd(file);

// Print the first three rows of 'y'
print y[1:3, .];

After the above code, the following ouptut should be printed to the Command window.

8910      3606.00      283.000      2.00000      34.0000
025      6645.00      483.000      3.00000      82.0000
593      7075.00      514.000      4.00000      71.0000

Load specified variables from a dataset¶

// Load all variables with a formula string
dat1 = loadd(file, "." );

// Load all observations of 'Balance' and 'Limit'
dat2 = loadd(file, "Balance + Limit" );

// Load all variables EXCEPT for 'Cards'
dat3 = loadd(file, ". - Cards" );

// Print first three rows of each matrix
print  "All variables: " dat1[1:3, .];
print  "Balance and Limit: " dat2[1:3, .];
print  "All except Cards: " dat3[1:3, .];

After the above code,

All variables:

891    3606.00    283.00    2.0000    34.000    11.000    1.0000    1.0000    2.0000    3.0000    333.000
03    6645.00    483.00    3.0000    82.000    15.000    2.0000    2.0000    2.0000    2.0000    903.000
59    7075.00    514.00    4.0000    71.000    11.000    1.0000    1.0000    1.0000    2.0000    580.000

Balance and Limit:

000      3606.00
000      6645.00
000      7075.00

All except Cards:

8910    3606.00    283.00    34.000    11.000    1.0000    1.0000    2.0000    3.0000    333.000
025    6645.00    483.00    82.000    15.000    2.0000    2.0000    2.0000    2.0000    903.000
593    7075.00    514.00    71.000    11.000    1.0000    1.0000    1.0000    2.0000    580.000

Load all columns of a GAUSS matrix file, .fmt¶

No variable names are stored in .fmt files. GAUSS allows the use of X1, X2, X2...XP to reference variables in a .fmt file.

// Create a matrix
x = rndn(10, 4);

// Save to a matrix file, 'x.fmt'
save x;

// Load all columns of 'x.fmt'
x_2 = loadd("x.fmt");

Load specified columns of a GAUSS matrix file, .fmt.¶

// Create a matrix
x = rndn(10, 4);

// Save to a matrix file, 'x.fmt'
save x;

// Load columns 2 and 4 from 'x.fmt'
x_2 = loadd("x.fmt", "X2 + X4");

Load three specified variables from a SAS dataset, .sas7bdat.¶

new;
cls;

dataset = getGAUSSHome() $+ "examples/detroit.dta";

// Create formula string specifying three variables to load
formula  = "homicide + unemployment + hourly_earn";

y = loadd(dataset, formula);

print "The dataset use is ";; dataset;
print "The number of variables equals: ";; cols(y);
print "The number of observations equals: ";; rows(y);

After the above code,

The dataset use is C:\gauss23\examples\detroit.dta
The number of variables equals:        3.0000000
The number of observations equals:        13.000000

Load a string date from a .csv file and automatically convert it to a POSIX date/time (seconds since Jan 1, 1970).¶

dataset = getGAUSSHome() $+ "examples/yellowstone.csv";

// Create formula string specifying that the column 'Date'
// from 'yellowstone.csv' is a string column (by using $) and
// that it should be loaded as a date with the 'date' keyword
formula  = "date($Date)";

// Load the date and convert to POSIX date/time format
dt_pos = loadd(dataset, formula);

// Convert the first 5 dates to a string 'Month day, Year'
// and print them
print posixToStrc(dt_pos[1:5], "%B %d, %Y");

After the above code,

January 01, 2016
January 01, 2015
January 01, 2014
January 01, 2013
January 01, 2012

Remarks¶

Since loadd() will load the entire dataset at once, the dataset must be small enough to fit in memory. To read chunks of a dataset in an iterative manner, use dataopen() and readr().
If dataset is a null string or 0, the dataset temp.dat will be loaded.
To load a matrix file, use an .fmt extension on dataset.
The supported dataset types are CSV, Excel (XLS, XLSX), HDF5, GAUSS Matrix (FMT), GAUSS Dataset (DAT), Stata (DTA) and SAS (SAS7BDAT, SAS7BCAT).
For HDF5 file, the dataset must include schema and both file name and dataset name must be provided, e.g.

loadd("h5://C:/gauss23/examples/testdata.h5/mydata").

Source¶

saveload.src

Globals¶

__maxvec

loadd¶

Purpose¶

Format¶

Examples¶

Load all contents of a GAUSS dataset¶

Load specified variables from a dataset¶

Load all columns of a GAUSS matrix file, .fmt¶

Load specified columns of a GAUSS matrix file, .fmt.¶

Load three specified variables from a SAS dataset, .sas7bdat.¶

Load a string date from a .csv file and automatically convert it to a POSIX date/time (seconds since Jan 1, 1970).¶

Remarks¶

Source¶

Globals¶

See also¶