Cascade Historian™ : Version 6.4
	Dynamic Library Functions

`hist_access_buffer`

hist_access_buffer — accesses buffer elements using array-like syntax.

Syntax

hist_access_buffer (buffer, index[, axis])

Parameters

buffer: A binary buffer of X-Y pairs of doubles, as created by a call to hist_buffer_id_read.
index: The index of the data element to retrieve from the buffer.
axis: An optional string indicating which value of the of the data pair to access, "X" or "Y".

Returns

If axis is specified, then the corresponding real-valued data at the index. If axis is not specified, then an instance of the HI_stVALUE class containing the data at the index. If an error occurs, then nil is returned and _last_error_ is set to one of the following possible errors:

"Invalid axis specifier: axis"
"Index out of range: index"
"Buffer empty"

Description

This function provides access to the elements of the buffer as if it were an array.

Example

Gamma> hist_access_buffer(buf, 2, "X");
1025721206.20266
Gamma> hist_access_buffer(buf, 2, "Y");
102.1
Gamma> hist_access_buffer(buf, 2);
{HI_stVALUE (value . 102.1) (xaxis . 1025721206.20266)}