- Boost-users - lists.preview.boost.org

[boost] Does boost 1.70 officially support VS2019 14.2 compiler
by Alex J 20 Jun '19

20 Jun '19

Hi, Does boost 1.70 officially support VS2019 14.2 compiler ? Boost.org doesn't explicitly say that they does or doesn't support VS2019 14.2. Also they have 14.1 listed as a "primary compiler tested". Thanks Alex

4 3

[release] 1.71.0 deadline for new libraries approaching
by Michael Caisse 19 Jun '19

19 Jun '19

One week from today master will closed for new libraries and breaking changes. Thanks, -- The Boost Release Team Boost Calendar with the release schedule: <http://www.boost.org/development/index.html>

1 0

How to set up user-config.jam properly?
by Robert Dailey 19 Jun '19

19 Jun '19

I am working on a user-config.jam file to build boost 1.70 against Android NDK r19. My jam file looks like this: ``` import os ; local ndk_cxx = [ os.environ CXX ] ; local ndk_ar = [ os.environ AR ] ; local ndk_ranlib = [ os.environ RANLIB ] ; local ndk_flags = [ os.environ CXXFLAGS ] ; using clang : x86 : "$(ndk_cxx)" : <cxxflags>"$(ndk_flags)" <archiver>"$(ndk_ar)" <ranlib>"$(ndk_ranlib)" <architecture>x86 <address-model>32 <binary-format>x86 <abi>x86 ; using clang : armeabi-v7a : "$(ndk_cxx)" : <cxxflags>"$(ndk_flags)" <archiver>"$(ndk_ar)" <ranlib>"$(ndk_ranlib)" <architecture>arm <address-model>32 <binary-format>elf <abi>aapcs ; ``` And my command line is: ``` ./bootstrap.sh --prefix=$INSTALL_DIR/boost || cat bootstrap.log ./b2 -j8 \ --without-python \ --without-test \ target-os=android \ toolset=clang-${ANDROID_ABI} \ variant=release \ threading=multi \ threadapi=pthread \ link=static \ runtime-link=shared \ install ``` When I run the commands above I get: ``` /_build/boost_1_70_0/tools/build/src/build/feature.jam:314: in implied-subfeature from module feature error: "armeabi" is not a known subfeature value of <toolset>clang /_build/boost_1_70_0/tools/build/src/build/feature.jam:497: in feature.validate-value-string from module feature /_build/boost_1_70_0/tools/build/src/build/property.jam:341: in validate1 from module property /_build/boost_1_70_0/tools/build/src/build/property.jam:367: in validate from module property /_build/boost_1_70_0/tools/build/src/build/property.jam:376: in property.validate-property-sets from module property /_build/boost_1_70_0/tools/build/src/build/toolset.jam:187: in toolset.flags from module toolset /_build/boost_1_70_0/tools/build/src/tools/common.jam:447: in common.handle-options from module common /_build/boost_1_70_0/tools/build/src/tools/clang-linux.jam:62: in clang-linux.init from module clang-linux /_build/boost_1_70_0/tools/build/src/build/toolset.jam:44: in toolset.using from module toolset /_build/boost_1_70_0/tools/build/src/tools/clang.jam:33: in clang.init from module clang /_build/boost_1_70_0/tools/build/src/build/toolset.jam:44: in toolset.using from module toolset /_build/boost_1_70_0/tools/build/src/build/project.jam:1104: in using from module project-rules /home/build/user-config.jam:28: in modules.load from module user-config /_build/boost_1_70_0/tools/build/src/build-system.jam:255: in load-config from module build-system /_build/boost_1_70_0/tools/build/src/build-system.jam:453: in load-configuration-files from module build-system /_build/boost_1_70_0/tools/build/src/build-system.jam:607: in load from module build-system /_build/boost_1_70_0/tools/build/src/kernel/modules.jam:295: in import from module modules /_build/boost_1_70_0/tools/build/src/kernel/bootstrap.jam:139: in boost-build from module /_build/boost_1_70_0/boost-build.jam:17: in module scope from module ``` The value of `ANDROID_ABI` is either `x86` or `armeabi-v7a`. What I'm not sure about is this syntax in the JAM file: ``` using <platform> : <subfeature> : <toolchain> ``` Why is this failing? Can someone explain this strange syntax in the JAM file? What is "subfeature" for and what values does it accept? How does this map to the command line arguments? How should I best set up my user config jam file for providing different build parameters per architecture in a cross-compilation setting (building for Android)?

1 1

Re: [Boost-users] [CMake] Specifying name of library file on CMake command line?
by Osman Zakir 17 Jun '19

17 Jun '19

From: Kyle Edwards <kyle.edwards(a)kitware.com> Sent: Monday, June 17, 2019 6:49 PM To: Osman Zakir; cmake(a)cmake.org Subject: Re: [CMake] Specifying name of library file on CMake command line? On Mon, 2019-06-17 at 13:47 +0000, Osman Zakir wrote: >> I want to know how to specify the name of a library I file I want to >> link against. How do I do this? I wanted to build a library with a >> static runtime and static libs; it requires linking against a Boost >> library which I did build with static runtime but when I tried to >> build it, I had linker errors because the dynamic version of the >> library was used instead of the static one. I want to somehow make >> it use the static one. So yeah, how do I do this? Is there a way? >Are you using the FindBoost module? >https://cmake.org/cmake/help/v3.14/module/FindBoost.html >Kyle Yes, I'm using that module. I didn't make any changes to it; it came with the third-party library I'm trying to build.

2 2

Boost.Units: unit type for dBm
by Carel Combrink 17 Jun '19

17 Jun '19

Hi, I have a system that uses dBm to indicate Signal Amplitude, how do I create a type using Boost.Units for this? At the moment I am not concerned about any type of conversions between power and this ratio. Any help will be appreciated. I am already using boost.unit successfully for other units and conversions with the help from the mailing list. I want to now define the correct strong type for this type for consistency. Regards, Carel

2 1

Building Boost.Python for a custom Python installation
by Evan Driscoll 14 Jun '19

14 Jun '19

I have a build of Python I made that was installed (--prefix) at ~/python-3.5.2-asan/. I want to build Boost.Python against it. I have Boost 1.70.0. I have tried a variety of permutations of passing various --with-python options and such to both bootstrap and b2 with no success. Perhaps the closest I've gotten is ./bootstrap.sh --prefix=$HOME/boost-1.70.0/ --with-python=$HOME/python-3.5.2-asan/bin/python3.5 python-debugging=on ./b2 --with-python python-debugging=on -d+2 -j8 cxxflags=-fsanitize=address cflags=-fsanitize=address but with those commands compilation fails because it is looking for include files in ...../include/python3.5/ instead of ..../include/python3.5dm While I'm at it, I had to add cflags and cxxflags explicitly instead of doing what some documentation [1] said to, because: ./b2 --with-python python-debugging=on -d+2 -j8 address-sanitizer=1 /home/evan/Downloads/boost_1_70_0/tools/build/src/build/feature.jam:327: in validate-feature from module feature error: unknown feature "<address-sanitizer>" [1] https://boostorg.github.io/build/manual/develop/index.html#_sanitizers Evan

1 0

[Process] Zombie Processes left behind
by Ryan Ruhge 05 Jun '19

05 Jun '19

Boost Team: We are trying to use boost process to have an always running process spawn child processes in a fire and forget manner (don't wait or block on the process that was just spawned). The issue we are running into is that the child processes become zombie processes when finished until the parent process completes. However in our system the parent process is never intended to complete, it is always running and listening. We have provided code snippets which give a simple example of the symptom we are experiencing. It's an infinite loop (imitating our always running process) that spawns processes that run and then become zombies instead of finishing (I included a sleep so it doesn't spawn processes too quickly). Please advise on whether there is something else we can do, if we are using child or spawn wrong, or if we are using boost process in a manner that it is not intended to be used. Thanks, Ryan Ruhge #include <boost/process.hpp> using namespace std; int main() { while (true) { boost::process::spawn("sleep 10"); sleep(5); } } #include <boost/process.hpp> using namespace std; int main() { while (true) { boost::process::child childProcess("sleep 10"); childProcess.detach(); sleep(5); } }

2 1

Downloads of boost from Bintray.com are temporarily unavailable
by Marshall Clow 30 May '19

30 May '19

Apparently, Boost is being downloaded over 6000 times/day from Bintray, and we've reached the limits of their bandwidth for the month. We're trying to get them to increase our quota (and see if there's someone who is downloading boost over and over again), but at the present time, downloads from bintray are being rejected. Hopefully this will be a temporary situation. -- Marshall (boost release manager)

1 0

Re: [Boost-users] catmull_rom splines
by Nick Thompson 30 May '19

30 May '19

Yes, the Catmull-Rom curve is confusing for scientific application developers because it *creates* a parametrization. For example, if you solved by stepper an ODE y' = f(t,y) and got a solution skeleton {t_i, y_i}, the Catmull-Rom curve *wouldn't accept the time points t_i*. It's only interested in the y_i. Since the Catmull-Rom curve is used in computer graphics, you can kinda see why those guys don't care what the parametrization is. I'm currently working on extending the barycentric rational interpolator into higher dimensions; mathematically it's trivial but getting the interface right is (as always) the real problem. Nick ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ On Thursday, May 30, 2019 8:52 AM, Giorgino R <giorginor21(a)gmail.com> wrote: > Dear Nick/all, > > That was my bad. > > I though that the parametrisation should be in the range [0-1] or [x_min-x_max]. I debugged my program and I saw that Catmull-Rom class internally change the parametrisation from 0 to m_max_s (for normal range 0 -1). Actually, it is explicitly mentioned in the documentation, as well. For some reason, I didn't interpret it properly. I attach my normal spline that now look as expected. > > Apologies for the trouble. It's because I have never had any previous experience with these type of splines. > > Many thanks > Giorgio > > On Thu, May 30, 2019 at 11:07 AM Giorgino R <giorginor21(a)gmail.com> wrote: > >> Dear Nick, >> >> Many thanks for your prompt reply along with your valuable suggestions. >> >> I have now added two ghost points at each end as you described; however, the curve looks (see the attached) more disappointing (always for my objectives :) ). >> To clarify, what I am trying to achieve is to get a (interpolation) line that passes through all the knots/points. Then, for a set of discrete x values (within the space of the line) I want to evaluate the corresponding points and pass them to a boost::linestring. I tried also with both [Cubic B-spline interpolation](https://www.boost.org/doc/libs/1_70_0/libs/math/doc/html/mat… and [Barycentric Rational Interpolation](https://www.boost.org/doc/libs/1_70_0/libs/math/doc/html/mat…. However, my sample points are not equally spaced and non-monotonic (x values). Therefore, I found that Catmull-Rom may be of better use here. >> >> The other issue that is unclear to myself is that the evaluation of a Catmull-Rom spline looks dependent on the parametrisation (see the two images in my first email), as well. >> >> Since in my application I am going to use Boost geometry, I would really like to find a solution on how to interpolate such data point sets with functionality available in Boost. >> >> Once again, many thanks for your support. >> >> Giorgio >> >> On Wed, May 29, 2019 at 6:32 PM Nick Thompson via Boost-users <boost-users(a)lists.boost.org> wrote: >> >>> Hi Giorgino, >>> >>> The strange behavior at the end of the Catmull-Rom splines is a deficiency of the method. However, we are fortunate that this is not a big deficiency. This is because the Catmull-Rom splines are interpolated by functions of compact support, so a point can influence at most four segments (only two, if the point is on the boundary). Looking at your images, I personally don't think they look bad. But presumably since you are writing this, you want better! >>> >>> I would recommend adding two ghost points. Draw a line between point 0 and point 1, and put the ghost point "in the mirror", i.e., place it where point 1 would appear if a mirror sat in the plane passing through P0 and orthogonal to the line joining point zero and point one. You might contend that this is an arbitrary choice, and it is! But the compact support of the basis functions means that the decision is not super important, and this choice will at least give reasonable-looking tangent vectors. >>> >>> Nick >>> >>> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ >>> On Wednesday, May 29, 2019 12:08 PM, Giorgino R via Boost-users <boost-users(a)lists.boost.org> wrote: >>> >>>> Hi all, >>>> >>>> I am trying to interpolate some data with a catmull_rom spline available in boost math (interpolation). However, the resulting spline has a strange behavior; especially, at its ends (see the attached image). >>>> Just out of curiosity, I also tried to normalise my data to [0-1] range. However, the line has had even worse behavior (see the attached image). >>>> Below, the c++ code segment of the interpolation is depicted: >>>> >>>> std::vector<std::array<double, 2>> points_intr(16); >>>> >>>> points_intr[0] = { 1.263270, 0.774614 }; >>>> points_intr[1] = { 1.876, 2.480 }; >>>> points_intr[2] = { 1.651110, 4.550 }; >>>> points_intr[3] = { 1.426340, 5.688 }; >>>> points_intr[4] = { 1.429, 7.054 }; >>>> points_intr[5] = { 2.073220, 8.377020 }; >>>> points_intr[6] = { 3.910, 9.140 }; >>>> points_intr[7] = { 6.430, 9.537 }; >>>> points_intr[8] = { 8.950, 9.859 }; >>>> points_intr[9] = { 11.470, 10.317 }; >>>> points_intr[10] = { 12.730, 10.6456 }; >>>> points_intr[11] = { 13.990, 11.0741 }; >>>> points_intr[12] = { 15.335, 11.6928 }; >>>> points_intr[13] = { 16.680, 12.5661 }; >>>> points_intr[14] = { 18.3538, 14.830 }; >>>> points_intr[15] = { 18.700, 16.056 }; >>>> >>>> bm::catmull_rom<std::array<double, 2>> >>>> interpolator_cr(std::move(points_intr)); >>>> >>>> std::vector<double> x_linspace_cr(100); >>>> std::vector<std::array<double, 2>> inter_points(100); >>>> linspace(1.263270, 18.700, 100, x_linspace_cr); // evaluation points along the line >>>> >>>> for (std::size_t i{0}; i < x_linspace_cr.size(); ++i) >>>> { >>>> inter_points[i] = interpolator_cr(x_linspace_cr[i]); >>>> } >>>> >>>> Should I have to add additional (ghost) points at both ends? If yes, is there any optimum way to calculate where exactly to poisition these points? I understand if I get the derivatives at both end I can calculate a straight line that the additional points should lie within. However, how should I calculate the distance from the end points? >>>> >>>> I hope I am not doing anything fundamentally wrong. Any help would be much appreciated. >>>> >>>> Many thanks! >>> >>> _______________________________________________ >>> Boost-users mailing list >>> Boost-users(a)lists.boost.org >>> https://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

catmull_rom splines
by Giorgino R 29 May '19

29 May '19

Hi all, I am trying to interpolate some data with a catmull_rom spline available in boost math (interpolation). However, the resulting spline has a strange behavior; especially, at its ends (see the attached image). Just out of curiosity, I also tried to normalise my data to [0-1] range. However, the line has had even worse behavior (see the attached image). Below, the c++ code segment of the interpolation is depicted: std::vector<std::array<double, 2>> points_intr(16); points_intr[0] = { 1.263270, 0.774614 }; points_intr[1] = { 1.876, 2.480 }; points_intr[2] = { 1.651110, 4.550 }; points_intr[3] = { 1.426340, 5.688 }; points_intr[4] = { 1.429, 7.054 }; points_intr[5] = { 2.073220, 8.377020 }; points_intr[6] = { 3.910, 9.140 }; points_intr[7] = { 6.430, 9.537 }; points_intr[8] = { 8.950, 9.859 }; points_intr[9] = { 11.470, 10.317 }; points_intr[10] = { 12.730, 10.6456 }; points_intr[11] = { 13.990, 11.0741 }; points_intr[12] = { 15.335, 11.6928 }; points_intr[13] = { 16.680, 12.5661 }; points_intr[14] = { 18.3538, 14.830 }; points_intr[15] = { 18.700, 16.056 }; bm::catmull_rom<std::array<double, 2>> interpolator_cr(std::move(points_intr)); std::vector<double> x_linspace_cr(100); std::vector<std::array<double, 2>> inter_points(100); linspace(1.263270, 18.700, 100, x_linspace_cr); // evaluation points along the line for (std::size_t i{0}; i < x_linspace_cr.size(); ++i) { inter_points[i] = interpolator_cr(x_linspace_cr[i]); } Should I have to add additional (ghost) points at both ends? If yes, is there any optimum way to calculate where exactly to poisition these points? I understand if I get the derivatives at both end I can calculate a straight line that the additional points should lie within. However, how should I calculate the distance from the end points? I hope I am not doing anything fundamentally wrong. Any help would be much appreciated. Many thanks!

2 1