mc_trajectory::SequenceInterpolator< Value, InterpolationFunction > Struct Template Reference
Interpolate values in a timed sequence. More...
#include <mc_trajectory/SequenceInterpolator.h>
Collaboration diagram for mc_trajectory::SequenceInterpolator< Value, InterpolationFunction >:
Public Types | |
| using | TimedValue = typename std::pair< double, Value > |
| using | TimedValueVector = std::vector< TimedValue > |
Public Member Functions | |
| SequenceInterpolator () noexcept | |
| Creates an empty interpolator. More... | |
| SequenceInterpolator (const TimedValueVector &values) | |
| Creates an interpolator with values. More... | |
| void | values (const TimedValueVector &values) |
| Set interpolator values. More... | |
| const TimedValueVector & | values () const noexcept |
| bool | hasValues () const noexcept |
| void | clear () |
| Value | compute (double currTime) |
Protected Attributes | |
| InterpolationFunction | interpolator_ |
| Functor for computing the interpolated values. More... | |
| TimedValueVector | values_ |
| Interpolation values. More... | |
| size_t | prevIndex_ = 0 |
| Cache the previous index to optimize lookup when used sequentially. More... | |
| size_t | nextIndex_ = 0 |
| Cache the next index. More... | |
| double | intervalDuration_ = 0 |
| Cache the duration of the current interval. More... | |
Detailed Description
template<typename Value, typename InterpolationFunction = LinearInterpolation<Value>>
struct mc_trajectory::SequenceInterpolator< Value, InterpolationFunction >
Interpolate values in a timed sequence.
This class provides an efficient and generic way to perform interpolation within a sequence of (sorted) intervals expressed as pairs of (time, Value):
- ensures that values are sorted by strictly ascending time
- selects the appropriate interval corresponding to the desired computation time
- O(log n) when interpolating at an arbitrary time (binary search)
- O(1) in most cases when used sequentially (the current interval is cached)
- perform interpolation by calling the InterpolationFunction functor on this interval (default: linear interpolation). The time ratio within the current interval is computed as a normalized value between 0 and 1. See LinearInterpolation for example.
InterpolationFunction::operator(const Value &intervalStart, const Value &intervalEnd, double ratio)
Example:
auto values = std::vector<double, double>
{
{0., 0.}, // time, value
{1., 100.},
{2., 200},
}
SequenceInterpolator<double> interp{values}; // Creates a linear interpolator
interp.compute(0); // Compute interpolation at time t = 0
interp.compute(0.005); // compute interpolation at time t = 0.005
interp.compute(1.2); // compute interpolation at time t = 1.2
...
- Template Parameters
-
Value Type of values to interpolate. It must meet the requirements of the InterpolationFunction (typically scalar-Value multiplication and Value-Value addition, e.g arithmetic types, Eigen::Vector, etc) InterpolationFunction Functor for computing the interpolated value.
Member Typedef Documentation
◆ TimedValue
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
| using mc_trajectory::SequenceInterpolator< Value, InterpolationFunction >::TimedValue = typename std::pair<double, Value> |
◆ TimedValueVector
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
| using mc_trajectory::SequenceInterpolator< Value, InterpolationFunction >::TimedValueVector = std::vector<TimedValue> |
Constructor & Destructor Documentation
◆ SequenceInterpolator() [1/2]
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
|
inlinenoexcept |
◆ SequenceInterpolator() [2/2]
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
|
inline |
Creates an interpolator with values.
- Parameters
-
values Values must respect the conditions describes in values
- Exceptions
-
std::runtime_error If values are invalid
Member Function Documentation
◆ clear()
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
|
inline |
Clears all values
◆ compute()
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
|
inline |
Compute interpolated value at the provided time
Calls the interpolation functor with time normalized between 0 and 1
InterpolationFunction::operator(const Value &, const Value &, double ratio)
{.cpp}
- Parameters
-
currTime Time at which to compute the interpolation. Out-of-bound access return the first or last value.
- Exceptions
-
std::runtime_error If values() is empty
◆ hasValues()
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
|
inlinenoexcept |
When true, this interpolator is in a valid state and compute will always return a valid value.
◆ values() [1/2]
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
|
inlinenoexcept |
Interpolation values
◆ values() [2/2]
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
|
inline |
Member Data Documentation
◆ interpolator_
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
|
protected |
Functor for computing the interpolated values.
◆ intervalDuration_
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
|
protected |
Cache the duration of the current interval.
◆ nextIndex_
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
|
protected |
Cache the next index.
◆ prevIndex_
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
|
protected |
Cache the previous index to optimize lookup when used sequentially.
◆ values_
template<typename Value , typename InterpolationFunction = LinearInterpolation<Value>>
|
protected |
Interpolation values.
The documentation for this struct was generated from the following file:
- include/mc_trajectory/SequenceInterpolator.h
