gtsam/python/gtsam_utils/plot.py

import numpy as np
import matplotlib.pyplot as plt

def plotPoint3OnAxes(ax, point, linespec):
    ax.plot([point.x()], [point.y()], [point.z()], linespec)

def plotPoint3(fignum, point, linespec):
    fig = plt.figure(fignum)
    ax = fig.gca(projection='3d')
    plotPoint3OnAxes(ax, point, linespec)

def plot3DPoints(fignum, values, linespec, marginals=None):
    # PLOT3DPOINTS Plots the Point3's in a values, with optional covariances
    #    Finds all the Point3 objects in the given Values object and plots them.
    #  If a Marginals object is given, this function will also plot marginal
    #  covariance ellipses for each point.

    keys = values.keys()

    # Plot points and covariance matrices
    for key in keys:
        try:
            p = values.atPoint3(key);
            # if haveMarginals
            #     P = marginals.marginalCovariance(key);
            #     gtsam.plotPoint3(p, linespec, P);
            # else
            plotPoint3(fignum, p, linespec);
        except RuntimeError:
            continue
            # I guess it's not a Point3

def plotPose3OnAxes(ax, pose, axisLength=0.1):
    # get rotation and translation (center)
    gRp = pose.rotation().matrix()  # rotation from pose to global
    C = pose.translation()

    # draw the camera axes
    xAxis = C + gRp[:, 0] * axisLength
    L = np.append(C[np.newaxis], xAxis[np.newaxis], axis=0)
    ax.plot(L[:, 0], L[:, 1], L[:, 2], 'r-')

    yAxis = C + gRp[:, 1] * axisLength
    L = np.append(C[np.newaxis], yAxis[np.newaxis], axis=0)
    ax.plot(L[:, 0], L[:, 1], L[:, 2], 'g-')

    zAxis = C + gRp[:, 2] * axisLength
    L = np.append(C[np.newaxis], zAxis[np.newaxis], axis=0)
    ax.plot(L[:, 0], L[:, 1], L[:, 2], 'b-')

    # # plot the covariance
    # if (nargin>2) && (~isempty(P))
    #     pPp = P(4:6,4:6); % covariance matrix in pose coordinate frame
    #     gPp = gRp*pPp*gRp'; % convert the covariance matrix to global coordinate frame
    #     gtsam.covarianceEllipse3D(C,gPp);
    # end

def plotPose3(fignum, pose, axisLength=0.1):
    # get figure object
    fig = plt.figure(fignum)
    ax = fig.gca(projection='3d')
    plotPose3OnAxes(ax, pose, axisLength)