How to create bearing factors (without range)?

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S Chatzizacharias

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Mar 12, 2021, 5:04:13 AM3/12/21
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Hello. I'm new to gtsam and I am trying to add some bearing factors in a nonlinear factor graph. The examples I found show only the bearing/range factor implementation. How can I do it without the range measurements? 

I tried this way:

// Create bearing factor from current pose to door point
Rot2 bearing_ang = Rot2::fromDegrees(13);
auto bearingNoise = noiseModel::Diagonal::Sigmas(Vector(0.1));
graph.emplace_shared<BearingFactor<Pose2, Point2>> (next_pose_num, next_door_num, bearing_ang, bearingNoise);

But I get a warning and an error while compiling:

/usr/local/include/gtsam/slam/BearingFactor.h:17:2: warning: #warning "BearingFactor is now an ExpressionFactor in SAM directory" [-Wcpp]
 #warning "BearingFactor is now an ExpressionFactor in SAM directory"

/usr/local/include/gtsam/3rdparty/Eigen/Eigen/src/Core/PlainObjectBase.h:778:7: error: static assertion failed: FLOATING_POINT_ARGUMENT_PASSED__INTEGER_WAS_EXPECTED
       EIGEN_STATIC_ASSERT(is_integer,

Also, I am not sure how to declare the bearing noise, since it is 1-dimensional measurement, so no matrix is required. 

Any feedback is appreciated.


Dellaert, Frank

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Mar 12, 2021, 3:27:55 PM3/12/21
to S Chatzizacharias, gtsam users
There is a bearing-only factor if I am not mistaken

Frank
From: gtsam...@googlegroups.com <gtsam...@googlegroups.com> on behalf of S Chatzizacharias <spyros...@gmail.com>
Sent: Friday, March 12, 2021 5:04:13 AM
To: gtsam users <gtsam...@googlegroups.com>
Subject: [GTSAM] How to create bearing factors (without range)?
 
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Dellaert, Frank

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Mar 12, 2021, 3:29:35 PM3/12/21
to S Chatzizacharias, gtsam users
In sam directory, *not* slam :-)

Frank
From: gtsam...@googlegroups.com <gtsam...@googlegroups.com> on behalf of Dellaert, Frank <frank.d...@cc.gatech.edu>
Sent: Friday, March 12, 2021 3:27:53 PM
To: S Chatzizacharias <spyros...@gmail.com>; gtsam users <gtsam...@googlegroups.com>
Subject: Re: [GTSAM] How to create bearing factors (without range)?
 

S Chatzizacharias

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Mar 15, 2021, 9:02:24 AM3/15/21
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Can you please direct me to some code samples that use this type of factor? (including the initialization and the noise model).

Also, I don't understand what that warning means. Should it be in the SLAM directory? and how can I change it? I don't remember choosing a directory to save it. I just include the header file:

#include <gtsam/slam/BearingFactor.h>

at the beginning of my code.

Dellaert, Frank

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Mar 15, 2021, 9:32:03 AM3/15/21
to S Chatzizacharias, gtsam users
Please use

#include <gtsam/sam/BearingFactor.h>

Sent: Monday, March 15, 2021 09:02
To: gtsam users <gtsam...@googlegroups.com>

S Chatzizacharias

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Mar 15, 2021, 9:48:16 AM3/15/21
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ok. Now I see. This removed the warning during compiling. Thanks!
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