Matlab grabs the stdout, stderr, stdin
handles of a Gfortran
program, even when using Java ProcessBuilder.
Disable this capture to allow external languages like Java to capture the output.
Just before the external process is started in the Matlab script:
If given a link that is suspect, or troubleshooting behavior of a website that is having trouble doing a redirect, check the HTTP header for a redirect.
Curl does this with the
–head
option.
curl --head example.invalid
This will return the HTTP header, which will show if there is a redirect, and where it is redirecting to.
Some web servers behave differently to a HEAD request than a GET request.
To see the behavior of a GET request, use the
–location
option to follow redirects.
The RISC-V based Raspberry Pi Pico microcontroller is commonly used for analog and digital control, optionally with WiFi or Bluetooth wireless connectivity.
While the full Raspberry Pi boards have a general purpose ARM CPU with enough storage and RAM capable of being used as a PC, the Pico is not commonly used for general purpose computing.
The multi-core CPU of the Pi Pico is capable of running parallel multi-threaded programs.
The Pico Cortex-M or RISC-V Hazard3 CPUs lacks a memory management unit (MMU).
Without an MMU, the Pico is not so effective at running a preemptive multitasking OS like a full Linux distribution.
However, it is possible to run a minimal Linux kernel and user space.
Provided a Pico board with enough memory, it’s possible to
run a minimal Linux distribution
on the Pico.
The analog and digital I/O pins can be used for
VGA output
from the Pico.
The Jetson Nano board has gone through several generations.
Older Jetson Nano boards may be stuck on an older unsupported OS.
If compatible with the specific Nano version hardware, the
NVIDIA Jetpack SDK
may be used to install a newer OS.
Select a
Jetson container
suitable for the desired task and hardware.
Operating systems require a certain minimum ISA microarchitecture level to run for each CPU vendor family.
The levels are arbitrarily defined by the vendor as a collection of features, for example AVX2 or AVX512.
A C++-based
cpuid library
can detect across operating systems if the Intel CPU supports a certain ISA level.
On macOS, Terminal commands can be specified to run with Rosetta using the arch command.
This is useful for running or testing x86_64 software on Apple Silicon Macs.
See “man arch” for more details.
A Fortran submodule may be defined in the same file or a different file than the Fortran module that uses the submodule.
Meta-build systems such as CMake and Meson are aware that each Fortran compiler has distinct Fortran submodule naming conventions.
Fortran module and submodule interface files are like generated header files.
The order of the commands for each compiler is significant and handled by the meta build system.
The Fortran module must be built before the Fortran submodule to generate the necessary module interface files BEFORE compiling the submodule.
Each compiler creates corresponding basic.o and basic_sub.o object files.
“module” are the files generated by step #1, building the file containing the Fortran module.
“submodule” are the files generated by step #2, building the containing the Fortran submodule.
GCC Gfortran module and submodule naming convention is defined in
module.cc
by definintions “MODULE_EXTENSION” and “SUBMODULE_EXTENSION”.
LLVM Flang module and submodule naming convention is defined in Semantics.
The table above is derived from the two-file example program:
file basic.f90
module demo
real, parameter:: pi =4.*atan(1.)
real:: tau
interfacemodulesubroutine hello(pi,tau)
real, intent(in) :: pi
real, intent(out) :: tau
endsubroutine hello
endinterfacecontainsendmodule demo
program sm
use demo
call hello(pi, tau)
print*,'pi=',pi, 'tau=', tau
endprogram
file basic_sub.f90
submodule (demo) hi
containsmoduleprocedure hello
tau =2*pi
endprocedure hello
endsubmodule hi
The Fortran standard does not define a specific Fortran module file format.
Each compiler vendor has a unique incompatible Fortran module file format.
Fortran module files are not portable between different compilers or even different versions of the same compiler.
The per-compiler examples below assume Fortran source file “example.f90”:
module dummy
real, parameter:: pi =4*atan(1.0)
containsrealfunction tau()
tau =2*pi
endfunction tau
endmodule dummy
Intel oneAPI .mod files are
a proprietary binary format.
It is possible to determine the version of the .mod file by using
od
to look at the first 2 bytes of the .mod file.
od -N4 -d dummy.mod
The first number is like “13” and is the module format version.
This version may change over time as oneAPI internals change.
The second number is the update version, which is fixed at “1”.
NVIDIA HPC SDK (NVHPC) and AOCC compilers generate .mod files that are text files.
The format for legacy Flang module files is distinct than flang-new Fortran module files.
Create the .mod file like:
nvfortran -c example.f90
# orflang -c example.f90
generates a text file, beginning with the version number.
By default, Cray Fortran stores uppercase DUMMY.mod filenames.
This can be made lowercase witht the ftn -ef flag.
The
Cray Fortran .mod format
is proprietary, but the version number might be seen like:
Matlab function arguments since R2021a can use name-value pairs.
GNU Octave already supported this syntax.
This is a convenient way to pass optional parameters to functions. The syntax is:
myfun(Name1=Value1, Name2=Value2, ...)
where Name1, Name2, … are the names of the parameters and Value1, Value2, … are the corresponding values.
The previous syntax for optional parameters is still supported:
The Pacman package manager by default says “checking available disk space” before installing or upgrading packages.
This can take an excessively long time (especially on Windows with MSYS2) when a large number of packages are being installed or upgraded.
To disable this behavior, edit the /etc/pacman.conf file and find and comment out: