Legacy Plotting API chart types

The Legacy plot method may be used to create several chart types, including:

• XY series plots
• Category plots
• Category histograms
• Histograms
• Pie charts
• OHLC plots
• Error bar plots

XY Series

An XY series plot is generally used to show values over a continuum, such as time. XY Series plots can be represented as a line, a bar, an area or as a collection of points. The X axis is used to show the domain, while the Y axis shows the related values at specific points in the range.

XY Series plots can be created using data from tables, arrays and functions.

XY Series Plot using Data from a Table

When data is sourced from a table, the following syntax can be used to create an XY Series plot:

.plot("SeriesName", source, "xCol", "yCol").show()

• plot is the method used to create an XY series plot.
• "SeriesName" is the name (as a string) you want to use to identify the series on the plot itself.
• source is the table that holds the data you want to plot.
• "xCol" is the name of the column of data to be used for the X value.
• "yCol" is the name of the column of data to be used for the Y value.
• show tells Deephaven to draw the plot in the console.

The example query below will create an XY series plot that shows the price of a single security (AAPL) over time.

XY Series Plot using Data from an Array

When data is sourced from an array, the following syntax can be used to create an XY Series plot:

.plot("SeriesName", [x], [y]).show()

• plot is the method used to create an XY series plot.
• "SeriesName" is the name (as a string) you want to use to identify the series on the plot itself.
• [x] is the array containing the data to be used for the X value.
• [y] is the array containing the data to be used for the Y value.
• show tells Deephaven to draw the plot in the console.

XY Series Plot using Data from a Function

When data is sourced from a function, the following syntax can be used to create an XY Series plot:

.plot("SeriesName", function).show()

• plot is the method used to create an XY series plot.
• "SeriesName" is the name (as a string) you want to use to identify the series on the plot itself.
• function is a mathematical operation that maps one value to another. Examples of Groovy functions and their formatting follow:
  • {x->x+100} adds 100 to the value of x.
  • {x->x*x} squares the value of x.
  • {x->1/x} uses the inverse of x.
  • {x->x*9/5+32} Fahrenheit to Celsius conversion.
• show tells Deephaven to draw the plot in the console.

Special considerations when plotting from a function

If you are plotting a function in a plot by itself, consider applying a range for the function using the funcRange or xRange method. Otherwise, the default value ([0,1]) will be used, which may not meet your requirements:

.plot("Function", {x->x*x} ).funcRange(0,10).show()

If the function is being plotted with other data series, the funcRange method is not needed, and the range will be obtained from the other data series.

When using a function plot, you may also want to increase or decrease the granularity of the plot by declaring the number of points to include in the range. This is configurable using the funcNPoints method:

.plot("Function", {x->x*x} ).funcRange(0,10).funcNPoints(55).show()

XY Series with Shared Axes

You can compare multiple series over the same period of time by creating an XY series plot with shared axes. In the following example, two series are plotted, thereby creating two line graphs on the same plot.

Subsequent series can be added to the plot by adding additional plot() methods to the query. However, the plotBy() method can also be used to do this.

XY Series with Multiple X or Y Axes

When plotting multiple series in a single plot, the range of the Y axis is an important factor to watch. In the previous example, both securities had values within in a relatively narrow range (31 to 35). Therefore, any change in values was easy to visualize. However, as the range of the Y axis increases, those changes become harder to assess.

To demonstrate this, let's plot AAPL and GOOG on the same chart:

Now, the scale of the Y axis needs to cover a much wider range (from 150 to 950), which results in relatively flat lines with barely distinguishable differences in values or trend.

This issue can be easily remedied by adding a second Y axis to the plot via the twinX() method.

twinX

The twinX() method enables you to use one Y axis for some of the series being plotted and a second Y axis for the others, while sharing the same X axis:

PlotName = figure().plot(...).twinX().plot(...).show()

• The plot(s) for the series placed before the twinX() method share a common Y axis (on the left).
• The plot(s) for the series listed after the twinX() method share a common Y axis (on the right).
• All plots share the same X axis.

For example, we can create an improved chart for AAPL and GOOG together:

The value range for AAPL is shown on the left axis and the value range for GOOG is shown on the right axis:

twinY

The twinY() method enables you to use one X axis for one set of the values being plotted and a second X axis for another, while sharing the same Y axis:

PlotName = figure().plot(...).twinY().plot(...).show()

• The plot(s) for the series placed before the twinY() method use the lower X axis.
• The plot(s) for the series listed after the twinY() method use the upper X axis.

XY Series with Plot Styles

The XY series plot in Deephaven defaults to a line plot. However, Deephaven's plotStyle() method can be used to format XY series plots as area charts, stacked area charts, bar charts, stacked bar charts, scatter charts and step charts.

In any of the examples below, you can simply swap out the .plotStyle() argument with the appropriate name; e.g., ("area"), ("stacked_area"), ("step"), etc.

XY Series as a Stacked Area Plot

XY Series as a Scatter Plot

XY Series as a Step Plot

Category

Category plots display data values from different discrete categories. They can be created using data from tables and arrays.

Category Plot using Data from a Table

When data is sourced from a table, the following syntax can be used to create a category:

.catPlot("SeriesName", source, "CategoryCol", "ValueCol").show()

• catPlot is the method used to create a category plot.
• "SeriesName" is the name (string) you want to use to identify the series on the plot itself.
• source is the table that holds the data you want to plot.
• "CategoryCol" is the name of the column (as a string) to be used for the categories.
• "ValueCol" is the name of the column (as a string) to be used for the values.
• show tells Deephaven to draw the plot in the console.

Category Plot using Data from Arrays

When data is sourced from a array, the following syntax can be used to create a category:

.catPlot("SeriesName", [category], [values]).show()

• catPlot is the method used to create a category plot.
• "SeriesName" is the name (as a string) you want to use to identify the series on the chart itself.
• [category] is the array containing the data to be used for the X values.
• [values] is the array containing the data to be used for the Y values.
• show tells Deephaven to draw the plot in the console.

Categories with Shared Axes

You can also compare multiple categories over the same period of time by creating a category plot with shared axes. In the following example, a second category plot has been added to the previous example, thereby creating bar graphs on the same chart:

Subsequent categories can be added to the chart by adding additional catPlot() methods to the query. However, the plotBy() method can also be used to do this.

Category charts with Plot Styles

By default, values are presented as vertical bars. However, by using Deephaven's plotStyle() method, the data can be represented as a bar, a stacked bar, a line, an area or a stacked area.

In any of the examples below, you can simply swap out the .plotStyle() argument with the appropriate name; e.g., ("Area"), ("stacked_area"), etc.

Category Plot with Stacked Bar

Multiple Sets of Stacked Category Plots

Multiple sets of stacked category plots can be created by assigning each category to a group and then applying a plot style:

Category Histogram

The category histogram plot is used to show how frequently a set of discrete values (categories) occur. They can be plotted using data from tables or arrays.

Category Histogram Plot using Data from a Table

When data is sourced from a table, the following syntax can be used:

.catHistPlot("seriesName", source, "ValueCol").show()

• catHistPlot is the method used to create a category histogram.
• "SeriesName" is the name (as a string) you want to use to identify the series on the chart itself.
• source is the table that holds the data you want to plot.
• "ValueCol" is the name of the column (as a string) containing the discrete values.
• show tells Deephaven to draw the plot in the console.

This query plots the histogram as follows:

• catHistTradesBySym is the name of the variable that will hold the plot.
• catHistPlot is the method.
• "Number of Trades" is the name of the series to use in the plot.
• trades is the table from which our data is being pulled.
• Sym is the name of the column containing the discrete values.
• chartTitle("Trades per Symbol") adds a chart title to the plot.

Category Histogram Plot using Data from an Array

When data is sourced from an array, the following syntax can be used:

.catHistPlot("SeriesName", [Values]).show()

• catHistPlot is the method used to create a category histogram.
• "SeriesName" is the name (as a string) you want to use to identify the series on the plot itself.
• [Values] is the array containing the discrete values.
• show tells Deephaven to draw the plot in the console.

Histogram

The histogram is used to show how frequently different data values occur. The data is divided into logical intervals (or bins) , which are then aggregated and charted with vertical bars. Unlike bar charts (category plots), bars in histograms do not have spaces between them unless there is a gap in the data. Histograms can be plotted using data from tables or arrays.

Histogram Plot using Data from a Table

When data is sourced from a table, the following syntax can be used:

.histPlot("seriesName", source, "ValueCol", nbins).show()

• histPlot is the method used to create a histogram.
• "SeriesName" is the name (as a string) you want to use to identify the series on the chart itself.
• source is the table that holds the data you want to plot.
• "ValueCol" is the name of the column (as a string) of data to be used for the X values.
• nbins is the number of intervals to use in the chart.
• show tells Deephaven to draw the plot in the console.

This query plots the histogram as follows:

• plotPriceIntervals is the name of the variable that will hold the chart.
• histPlot is the method.
• "AAPL" is the name of the series to use in the chart.
• trades.where("Sym=`AAPL`") is the source data filtered to AAPL.
• Last is table column that contains the values we want to plot, and
• 10 is the number of intervals we want to use to divide up the sales.

The histPlot method assumes you want to plot the entire range of values in the dataset. However, you can also set the minimum and maximum values of the range using rangeMin and rangeMax respectively:

.histPlot("seriesName", source, "ValueCol", rangeMin, rangeMax, nbins).show()

• histPlot is the method used to create a histogram.
• "SeriesName" is the name (as a string) you want to use to identify the series on the chart itself.
• source is the table that holds the data you want to plot.
• "ValueCol" is the name of the column (as a string) of data to be used for the X values.
• rangeMin is the minimum value (as a double) of the range to be included.
• rangeMax is the maximum value (as a double) of the range to be included.
• nbins is the number of intervals to use in the chart.
• show tells Deephaven to draw the plot in the console.

Histogram Plot using Data from an Array

When data is sourced from an array, the following syntax can be used:

.histPlot("SeriesName", [x], nbins).show()

• histPlot is the method used to create a histogram.
• "SeriesName" is the name (as a string) you want to use to identify the series on the chart itself.
• [x] is the array containing the data to be used for the X values.
• nbins is the number of intervals to use in the chart.
• show tells Deephaven to draw the plot in the console.

The histPlot method assumes you want to plot the entire range of values in the dataset. However, you can also set the minimum and maximum values of the range using rangeMin and rangeMax respectively:

.histPlot("SeriesName", [x], rangeMin, rangeMax, nbins).show()

• histPlot is the method used to create a histogram.
• "SeriesName" is the name (as a string) you want to use to identify the series on the chart itself.
• [x] is the array containing the data to be used for the X values.
• rangeMin is the minimum value (as a double) of the range to be included.
• rangeMax is the maximum value (as a double) of the range to be included.
• nbins is the number of the intervals to use in the chart.
• show tells Deephaven to draw the plot in the console.

OHLC

The Open, High, Low and Close (OHLC) plot typically shows four prices of a security or commodity per time slice: the open and close of the time slice, and the highest and lowest values reached during the time slice.

This plotting method requires a dataset that includes one column containing the values for the X axis (time), and one column for each of the corresponding four values (open, high, low, close). Open, High, Low and Close Plots can be created using data from tables or arrays.

OHLC Plot using Data from a Table

When data is sourced from a table, the following syntax can be used:

.ohlcPlot("SeriesName", source, "Time", "Open", "High", "Low", "Close").show()

• ohlcPlot is the method used to create an OHLC chart.
• "SeriesName" is the name (as a string) you want to use to identify the series on the chart itself.
• source is the table that holds the data you want to plot.
• "Time" is the name (as a string) of the column to be used for the X axis.
• "Open" is the name of the column (as a string) holding the opening price.
• "High" is the name of the column (as a string) holding the highest price.
• "Low" is the name of the column (as a string) holding the lowest price.
• "Close" is the name of the column (as a string) holding the closing price.
• show tells Deephaven to draw the plot in the console.

This query plots the OHLC chart as follows:

• plotOHLC is the name of the variable that will hold the chart.
• ohlcPlot is the method.
• "AAPL" is the name of the series to be used in the chart.
• tOHLC is the table from which our data is being pulled.
• EODTimestamp is the name of the column to be used for the X axis.
• "Open", "High", "Low", and "Close", are the names of the columns containing the four respective data points to be plotted on the Y axis.
• xBusinessTime() limits the date to business days only.
• lineStyle() and chartTitle() provide component formatting to the table. 2 refers to line width.

OHLC Plot using Data from an Array

When data is sourced from an array, the following syntax can be used:

.ohlcPlot("SeriesName",[Time], [Open], [High], [Low], [Close]).show()

• ohlcPlot is the method used to create an OHLC chart.
• "SeriesName" is the name (as a string) you want to use to identify the series on the chart itself.
• [Time] is the array containing the data to be used for the X axis.
• [Open] is the array containing the data to be used for the opening price.
• [High] is the array containing the data to be used for the highest price.
• [Low] is the array containing the data to be used for the lowest price.
• [Close] is the array containing the data to be used for the closing price.
• show tells Deephaven to draw the plot in the console.

OHLC Plots with Shared Axes

Just like XY series plots, the Open, High, Low and Close plot can also be used to present multiple series on the same chart, including the use of multiple X or Y axes. An example of this follows:

This query plots the OHLC chart as follows:

• plotOHLC2 is the name of the variable that will hold the chart.
  • ohlcPlot plots the first series.
  • "AAPL" is the name of the first series to be used in the chart.
  • t2OHLC is the table from which the data is being pulled.
  • where("Ticker=`AAPL`") filters the table to only the AAPL Ticker.
  • EODTimestamp is the name of the column to be used for the X axis.
  • "Open", "High", "Low", and "Close", are the names of the columns containing the four respective data points to be plotted on the Y axis.
  • The lineStyle() method needs to be assigned to each series, so this reference only applies to the first series.
• twinX is used to show different Y axes.
• ohlcPlot plots the second series.
  • "MSFT" is the name of the second series to be used in the chart.
  • t2OHLC is the table from which the data is being pulled.
  • where("Ticker=`MSFT`") filters the table to only the MSFT Ticker.
  • EODTimestamp is the name of the column to be used for the X axis.
  • "Open", "High", "Low", and "Close", are the names of the columns containing the four respective data points to be plotted on the Y axis.
  • lineStyle() applies only to the second series.
• xBusinessTime() limits the date to business days only.
• chartTitle() provides the title for the chart.

In this plot, the opening, high, low and closing price of AAPL and MSFT are plotted. The twinX() method is used to show the value scale for AAPL on the left Y axis and the value scale for MSFT on the right Y axis.

Pie

The pie plot shows data as sections of a circle to represent the relative proportion for each of the categories that make up the entire dataset being plotted.

Pies plots can be created using data from tables or arrays.

Pie Plot using Data from a Table

When data is sourced from a table, the following syntax can be used to create a pie plot:

.piePlot("SeriesName", source, "CategoryCol", "ValueCol").show()

• piePlot is the method used to create a pie plot.
• "SeriesName" is the name (as a string) you want to use to identify the series on the plot itself.
• source is the table that holds the data you want to plot.
• "CategoryCol" is the name of the column (as a string) to be used for the categories.
• "ValueCol" is the name of the column (as a string) to be used for the values.
• show tells Deephaven to draw the plot in the console.

Pie Plot using Data from an Array

When data is sourced from an array, the following syntax can be used:

.piePlot("SeriesName", [category], [values]").show()

• piePlot is the method used to create a pie chart.
• "SeriesName" is the name (as a string) you want to use to identify the series on the chart.
• [category] is the array containing the data to be used for the X values.
• [values] is the array containing the data to be used for the Y values.
• show tells Deephaven to draw the plot in the console.

Related documentation

• Error Bar Plotting
• Component Formatting
• Visual Formatting