Wilders Smoothing

Function Prototype

/* Wilders Smoothing */
/* Type: overlay */
/* Input arrays: 1    Options: 1    Output arrays: 1 */
/* Inputs: real */
/* Options: period */
/* Outputs: wilders */
int ti_wilders_start(TI_REAL const *options);
int ti_wilders(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.

Wilder's smoothing is a type of exponential moving average.

It takes one parameter, the period n, a positive integer. Larger values for n will have a greater smoothing effect on the input data but will also create more lag.

It is calculated with the following formula:

It is equivalent to a 2n-1 Exponential Moving Average. For example, a 10 period Wilder's smoothing is the same as a 19 period exponential moving average.

The calculation is initialized by calculated the mean of the first n bars.

See Also

• Average True Range
• Exponential Moving Average

References

• Wilder, J. Welles (1978) New Concepts in Technical Trading Systems
• Achelis, S. (2000) Technical Analysis from A to Z, 2nd Edition
• Wikipedia: Exponential moving average

Example Usage

Calling From C

/* Example usage of Wilders Smoothing */
/* Assuming that 'input' is a pre-loaded array of size 'in_size'. */
TI_REAL *inputs[] = {input};
TI_REAL options[] = {5}; /* period */
TI_REAL *outputs[1]; /* wilders */

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

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

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

Calling From Lua (with Tulip Chart bindings)

-- Example usage of Wilders Smoothing
wilders = ti.wilders(input, 5)

Example Calculation

period = 5

Chart

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