getColDateFormats#

Purpose#

Gets BSD strftime format specifiers for specified columns of a dataframe.

Format#

fmt_date = getColDateFormats(X[, columns])#

Parameters:

X (NxK dataframe) – data with metadata.
columns (Mx1 scalar or string) – Optional argument, The names or indices of the date columns to query. Default = all columns.

Returns:

fmt_date (Mx1 string array) – contains the strftime date/time format characters corresponding to the columns of X specified by columns.

Examples#

The dataset for this example has two variables, TIMESTAMP and BIDPRICE. It looks like this:

 TIMESTAMP  BIDPRICE
1514826015   1.25505
1514826196   1.25515
1514826196   1.25518

The dates in the file are in POSIX time, seconds since Jan 1, 1970.

// Load exchange rate data
// First column is ticker times in POSIX format
fname = getGAUSShome $+ "examples/usd_cad_2018.dat";
usd_cad_2018 = loadd(fname);

// Specify format to represent
// Year-day-month Hour:Minute:Second
fmt = "%Y-%m-%d %H:%M:%S";
usd_cad_df = setColDateFormats(usd_cad_2018, fmt, "TIMESTAMP");

// Get data format of "TIMESTAMP" variable
fmt_timestamp = getColDateFormats(usd_cad_df, "TIMESTAMP");

Note

Column indices can also be used in place of the variable name like this, getColDateFormats(usd_cad_df, 1)

After the above code, the first few rows of usd_cad_df will look like this:

          TIMESTAMP   BIDPRICE
2018-01-01 17:00:15    1.25505
2018-01-01 17:03:16    1.25515
2018-01-01 17:03:16    1.25518

and fmt_time_stamp will be equal to:

%Y-%m-%d %H:%M:%S