# Money Flow Index

## Function Prototype

/* Money Flow Index */
/* Type: indicator */
/* Input arrays: 4    Options: 1    Output arrays: 1 */
/* Inputs: high, low, close, volume */
/* Options: period */
/* Outputs: mfi */
int ti_mfi_start(TI_REAL const *options);
int ti_mfi(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.

The Money Flow Index represents the amount of money flowing into and out of a security.

It takes one option, the period n.

Calculation is as follows:

$$tp_{t} = \frac{high_{t}+low_{t}+close_{t}}{3}$$
$$mf_{t} = tp_{t} \cdot volume_{t}$$
$$up_{t} = \sum_{i=0}^{n-1} \begin{cases} mf_{t-i} & \mathrm{if} \; tp_{t-i} > tp_{t-i-1} \\ 0 & \mathrm{else} \end{cases}$$
$$down_{t} = \sum_{i=0}^{n-1} \begin{cases} mf_{t-i} & \mathrm{if} \; tp_{t-i} \lt tp_{t-i-1} \\ 0 & \mathrm{else} \end{cases}$$
$$mfi_{t} = 100 - \frac{100}{1 + \frac{up_{t}}{down_{t}}}$$

## Example Usage

### Calling From C

/* Example usage of Money Flow Index */
/* Assuming that 'high', 'low', 'close', and 'volume' are pre-loaded arrays of size 'in_size'. */
TI_REAL *inputs[] = {high, low, close, volume};
TI_REAL options[] = {5}; /* period */
TI_REAL *outputs[1]; /* mfi */

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

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

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


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

-- Example usage of Money Flow Index
mfi = ti.mfi(high, low, close, volume, 5)


## Example Calculation

period = 5

datehighlowclosevolumemfi
2005-11-0182.1581.2981.595,653,100.00
2005-11-0281.8980.6481.066,447,400.00
2005-11-0383.0381.3182.877,690,900.00
2005-11-0483.3082.6583.003,831,400.00
2005-11-0783.8583.0783.614,455,100.00
2005-11-0883.9083.1183.153,798,000.0061.17
2005-11-0983.3382.4982.843,936,200.0067.31
2005-11-1084.3082.3083.994,732,000.0062.80
2005-11-1184.8484.1584.554,841,300.0064.66
2005-11-1485.0084.1184.363,915,300.0045.24
2005-11-1585.9084.0385.536,830,800.0067.84
2005-11-1686.5885.3986.546,694,100.0085.58
2005-11-1786.9885.7686.895,293,600.0085.96
2005-11-1888.0087.1787.777,985,800.0087.50
2005-11-2187.8787.0187.294,807,900.0084.65

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