# Vector Multiplication

## Function Prototype

/* Vector Multiplication */
/* Type: simple */
/* Input arrays: 2    Options: 0    Output arrays: 1 */
/* Inputs: real, real */
/* Options: none */
/* Outputs: mul */
int ti_mul_start(TI_REAL const *options);
int ti_mul(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.

Mul simply takes two input arrays and multiplies them.

$$mul_{t} = a_{t} b_{t}$$

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

## Example Usage

### Calling From C

/* Example usage of Vector Multiplication */
/* Assuming that 'input1' and 'input2' are pre-loaded arrays of size 'in_size'. */
TI_REAL *inputs[] = {input1, input2};
TI_REAL options[] = {}; /* No options */
TI_REAL *outputs[1]; /* mul */

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

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

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


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

-- Example usage of Vector Multiplication
mul = ti.mul(input1, input2)


## Example Calculation

dateinputinput2mul
2005-11-0181.5981.856,678.14
2005-11-0281.0681.206,582.07
2005-11-0382.8781.556,758.05
2005-11-0483.0082.916,881.53
2005-11-0783.6183.106,947.99
2005-11-0883.1583.416,935.54
2005-11-0982.8482.716,851.70
2005-11-1083.9982.706,945.97
2005-11-1184.5584.207,119.11
2005-11-1484.3684.257,107.33
2005-11-1585.5384.037,187.09
2005-11-1686.5485.457,394.84
2005-11-1786.8986.187,488.18
2005-11-1887.7788.007,723.76
2005-11-2187.2987.607,646.60

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