# Cosine Integral (G Dataflow)

Evaluates the cosine integral for any real nonnegative number.  ## x

A real nonnegative number. ## error in

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error  If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Default: No error ## Ci(x)

Result of the calculation of the cosine integral for the given value of x. ## error out

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error  If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

## Algorithm for Evaluating the Cosine Integral

The following equation defines the cosine integral.

$Ci\left(x\right)=\gamma +\mathrm{ln}\left(|x|\right)+{\int }_{0}^{x}\frac{\mathrm{cos}\left(t\right)-1}{t}dt$

where $\gamma$ is the Euler constant.

The following illustration shows the graph of the cosine integral in the interval (0, 15). Where This Node Can Run:

Desktop OS: Windows

FPGA: This product does not support FPGA devices