curvature.analysisRun.computeCurveLength

Description

Removes consecutive points closer than the app's duplicate tolerance and sums the Euclidean distance between the remaining adjacent points. A valid calibration converts the pixel length to the requested physical unit. The function does not smooth, interpolate, close the path, plot, or write files.

Inputs

xPix

Numeric x-coordinate vector in image pixels (image columns). At least two unique consecutive point pairs are required.

yPix

Numeric y-coordinate vector in image pixels (image rows), with the same number of elements as xPix.

calibration

Scale structure accepted by curvature.analysisRun.normalizeScaleCalibration. Empty or omitted input reports length in pixels.

Outputs

lengthResult

Scalar structure with the following fields.

Result Fields

ok, message - true and empty text after a successful calculation.

length_px

Sum of adjacent segment lengths in pixels.

length_show

length_px divided by pixelsPerUnit when calibrated; otherwise length_px.

unitLen

Calibration unit when calibrated, otherwise "px". referencePx, referenceLength, scaleUnit, px_per_unit,

usePhysicalScale

Effective scale metadata.

pointCount

Number of points remaining after duplicate removal.

Errors

labkit_CurvatureMeasurement_app:NotEnoughLengthPoints

Fewer than two unique points remain.

Example

x = [0 3 3];
y = [0 0 4];
result = curvature.analysisRun.computeCurveLength(x, y);
assert(result.length_px == 7 && result.unitLen == "px")