Still have questions?
Contact support

# Rate of change

## Overview

Rate of change (ROC) is a simple technical analysis indicator showing the difference between today's closing price and the close N days ago.

AnyChart Stock allows you to add ROC with desired period to any of your charts.

Mathematical description of the indicator: Rate of change (ROC) Mathematical Description.

ROC indicator is added using roc() method, it requires a mapping with the `"value"` field in it:

``````// create data table on loaded data
var dataTable = anychart.data.table();

// add data to a table

var mapping = dataTable.mapAs({'value': 4});

// create stock chart
chart = anychart.stock();

// create plot on the chart
var plot_0 = chart.plot(0);

// ROC is usually displayed on a separate plot
var plot_1 = chart.plot(1);

// create ROC indicator with period 14
var roc14 = plot_1.roc(mapping, 14).series();
roc14.stroke('#bf360c');
``````

Here is a live sample:

## Indicator Parameters

ROC indicator needs three parameters: mapping with the `"value"` field in it, period and a type of series to be displayed as:

``````var roc30 = plot.roc(mapping, 30, "column");
``````

## Visualization

Vizualization of an indicator depends on the type of a series you display it with. Here is a sample where ROC with different parameters and settings is added to different plots:

``````// create ROC indicator with period 14 and shown as column on the second plot
roc14 = plot_1.roc(mapping, 14).series();
roc14.stroke('#bf360c');

// create ROC indicator with period 30 and shown as column on the third plot
var roc30 = plot_2.roc(mapping, 30, "column").series();
roc30.fill('#ff6d00');
``````

Live sample: