# Vector Tangent

## Function Prototype

/* Vector Tangent */
/* Type: simple */
/* Input arrays: 1    Options: 0    Output arrays: 1 */
/* Inputs: real */
/* Options: none */
/* Outputs: tan */
int ti_tan_start(TI_REAL const *options);
int ti_tan(int size,
TI_REAL const *const *inputs,
TI_REAL const *options,
TI_REAL *const *outputs);

## Description

This documentation is still a work in progress. It has omissions, and it probably has errors too. If you see any issues, or have any general feedback, please get in touch.

Vector Tangent calculates the Trigonometric tangent of each element in the input array.

$$tan_{t} = \tan{input_{t}}$$

This is sometimes useful as a building block to more complex functions.

## Example Usage

### Calling From C

/* Example usage of Vector Tangent */
/* Assuming that 'input' is a pre-loaded array of size 'in_size'. */
TI_REAL *inputs[] = {input};
TI_REAL options[] = {}; /* No options */
TI_REAL *outputs[1]; /* tan */

/* Determine how large the output size is for our options. */
const int out_size = in_size - ti_tan_start(options);

/* Allocate memory for output. */
outputs[0] = malloc(sizeof(TI_REAL) * out_size); assert(outputs[0] != 0); /* tan */

/* Run the actual calculation. */
const int ret = ti_tan(in_size, inputs, options, outputs);
assert(ret == TI_OKAY);


### Calling From Lua (with Tulip Chart bindings)

-- Example usage of Vector Tangent
tan = ti.tan(input)


## Example Calculation

dateinputtan
2005-11-0181.59-0.09
2005-11-0281.06-0.72
2005-11-0382.872.49
2005-11-0483.003.88
2005-11-0783.61-2.68
2005-11-0883.159.75
2005-11-0982.842.29
2005-11-1083.99-1.10
2005-11-1184.55-0.28
2005-11-1484.36-0.50
2005-11-1585.530.85
2005-11-1686.54-6.79
2005-11-1786.89-1.85
2005-11-1887.77-0.20
2005-11-2187.29-0.80

## Other Indicators

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