## Introduction

LABVIEW includes the WAVEFORM GRAPH and chart to display data typically acquired at a constant rate. The waveform graph displays one or more plots of evenly sampled measurements. The waveform graph plots only single-valued functions, as in y = f (x), with points evenly distributed along the x-axis, such as acquired time-varying waveforms. The below Figure shows an example of a waveform graph. The waveform graph can display plots containing any number of points. The graph also accepts several data types, which minimizes the extent to which you must manipulate data before you display it. ## Displaying A Single Plot On Waveform Graphs

The waveform graph accepts several data types for single-plot waveform graphs. The graph accepts a single array of values, interprets the data as points on the graph and increments the x index by one starting at x = 0. The graph accepts a CLUSTER of an initial x value, a delta x and an array of y data. The graph also accepts the waveform data type, which carries the data, start time and delta t of a waveform. The waveform graph also accepts the dynamic data type, which is for use with Express VIS. In addition to the data associated with a signal, the dynamic data type includes attributes that provide information about the signal such as the name of the signal or the date and time the data was acquired. Attributes specify how the signal appears on the waveform graph. When the dynamic data type includes a single numeric value, the graph plots the single value and automatically formats the plot legend and x-scale time stamp. When the dynamic data type includes a single channel, the graph plots the whole waveform and automatically formats the plot legend and x-scale time stamp.

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## Displaying Multiple Plots On Waveform Graphs

The waveform graph accepts several data types for displaying multiple plots. The waveform graph accepts a 2D ARRAY of values, where each row of the array is a single plot. The graph interprets the data as points on the graph and increments the x index by one, starting at x = 0. Wire a 2D array data type to the graph, right-click the graph and select Transpose Array from the shortcut menu to handle each column of the array as a plot. This is particularly useful when you sample multiple channels from a DAQ device because the device can return the data as 2D arrays with each channel stored as a separate column. The waveform graph also accepts a cluster of an initial x value, a delta x value, and a 2D array of y data. The graph interprets the y data as points on the graph and increments the x index by delta x, starting at the initial x value. This data type is useful for displaying multiple signals that are sampled at the same regular rate. The waveform graph accepts a plot array where the array contains clusters. Each cluster contains a 1D array that contains the y data. The inner array describes the points in a plot, and the outer array has one cluster for each plot. The front panel in the below Figure shows the array of the y cluster. 