I'm starting out with Qt Creator and I'm working on mapping some key value pairs (AWG wire gauge sizes as keys and the diameter as value). In using QMap to create the map, I'm getting compile errors of 'awg_map does not name a type'. Can anyone point me in the right direction here?
I've tried adding values two ways that are supposed to work, according to the instructions found at http://doc.qt.io/qt-5/qmap.html. Both ways generate the error noted above.
#include <QMap>
QMap<QString, float> awg_map;
awg_map["20"] = 0.812;
awg_map.insert("21", 0.723);
Looks like G.M. was right with this comment
Statements such as awg_map["20"] = 0.812; and awg_map.insert("21",
0.723); aren't valid at global scope and should be in a function body (for example).
I dropped it all into the MainWindow::MainWindow and it compiled fine. Thanks for that one GM!
It's convenient to just use target_link_libraries(MyExecutable Qt5::Core), but when I do message(STATUS "Qt5Core_LIBRARIES=${Qt5Core_LIBRARIES}") I would expect it to return something like /opt/Qt/<...>/libQt5Core.so;/opt/<...>.so;[etc] instead of Qt5::Core. That doesn't really help me at all. Any way to get the actual list of libraries?
Thanks in advance! (Long time lurker, first time asker.)
Qt5::Core is an IMPORTED target, which has target_properties like any other target. I'd assume the property INTERFACE_LINK_LIBRARIES would give you what you seek.
Is there a way to resize a chunked dataset in HDF5 using Julia's HDF5.jl? I didn't see anything in the documentation. Looking through the source, all I found was set_dims!(), but that cannot extend a dataset (only shrink it). Does HDF5.jl have the ability to enlarge an existing (chunked) dataset? This is a very important feature for me, and I would rather not have to call into another language.
The docs have a brief mention of extendible dimensions in hdf5.md excerpted below.
You can use extendible dimensions,
d = d_create(parent, name, dtype, (dims, max_dims), "chunk", (chunk_dims), [lcpl, dcpl, dapl])
set_dims!(d, new_dims)
where dims is a tuple of integers. For example
b = d_create(fid, "b", Int, ((1000,),(-1,)), "chunk", (100,)) #-1 is equivalent to typemax(Hsize)
set_dims!(b, (10000,))
b[1:10000] = [1:10000]
I believe I've got it figured out. The issue is that I forgot to give the dataspace a large enough max_dims. Doing that required digging into the lower-level API. The solution I found was:
dspace = HDF5.dataspace((6,20)::Dims, max_dims=(6,typemax(Int64)))
dtype = HDF5.datatype(Float64)
dset = HDF5.d_create(prt, "trajectory", dtype, dspace, "chunk", (6,10))
Once I created a dataset that can be resized appropriately, the set_dims! function resizes the dataset correctly.
I think I located a few minor issues with the API, which I had to work around or change in my local version. I will get in touch with the HDF5.jl owner regarding those. For those interested:
The constant H5S_UNLIMITED is of type Uint64, but the dataspace function will only accept tuples of Int64, hence why I used typemax(Int64) for my max_dims to imitate how H5S_UNLIMITED is derived.
The form of d_create which I used calls h5d_create incorrectly; it passes parent instead of checkvalid(parent).id (can be seen by comparison with other forms of d_create).
I am making a C application in Unix that uses raw tty input.
I am calling write() to characters on the display, but I want to manipulate the cursor:
ssize_t
write(int d, const void *buf, size_t nbytes);
I've noticed that if buf has the value 8 (I mean char tmp = 8, then passing &tmp), it will move the cursor/pointer backward on the screen.
I was wondering where I could find all the codes, for example, I wish to move the cursor forward but I cannot seem to find it via Google.
Is there a page that lists all the code for the write() function please?
Thank you very much,
Jary
8 is just the ascii code for backspace. You can type man ascii and look at all the values (the man page on my Ubuntu box has friendlier names for the values). If you want to do more complicated things you may want to look at a library like ncurses.
You have just discovered that character code 8 is backspace (control-H).
You would probably be best off using the curses library to manage the screen. However, you can find out what control sequences curses knows about by using infocmp to decompile the terminfo entry for your terminal. The format isn't particularly easy to understand, but it is relatively comprehensive. The alternative is to find a manual for the terminal, which tends to be rather hard.
For instance, I'm using a color Xterm window; infocmp says:
# Reconstructed via infocmp from file: /usr/share/terminfo/78/xterm-color
xterm-color|nxterm|generic color xterm,
am, km, mir, msgr, xenl,
colors#8, cols#80, it#8, lines#24, ncv#, pairs#64,
acsc=``aaffggiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~,
bel=^G, bold=\E[1m, clear=\E[H\E[2J, cr=^M,
csr=\E[%i%p1%d;%p2%dr, cub=\E[%p1%dD, cub1=^H,
cud=\E[%p1%dB, cud1=^J, cuf=\E[%p1%dC, cuf1=\E[C,
cup=\E[%i%p1%d;%p2%dH, cuu=\E[%p1%dA, cuu1=\E[A,
dch=\E[%p1%dP, dch1=\E[P, dl=\E[%p1%dM, dl1=\E[M, ed=\E[J,
el=\E[K, enacs=\E)0, home=\E[H, ht=^I, hts=\EH, il=\E[%p1%dL,
il1=\E[L, ind=^J,
is2=\E[m\E[?7h\E[4l\E>\E7\E[r\E[?1;3;4;6l\E8, kbs=^H,
kcub1=\EOD, kcud1=\EOB, kcuf1=\EOC, kcuu1=\EOA,
kdch1=\E[3~, kf1=\E[11~, kf10=\E[21~, kf11=\E[23~,
kf12=\E[24~, kf13=\E[25~, kf14=\E[26~, kf15=\E[28~,
kf16=\E[29~, kf17=\E[31~, kf18=\E[32~, kf19=\E[33~,
kf2=\E[12~, kf20=\E[34~, kf3=\E[13~, kf4=\E[14~,
kf5=\E[15~, kf6=\E[17~, kf7=\E[18~, kf8=\E[19~, kf9=\E[20~,
kfnd=\E[1~, kich1=\E[2~, kmous=\E[M, knp=\E[6~, kpp=\E[5~,
kslt=\E[4~, meml=\El, memu=\Em, op=\E[m, rc=\E8, rev=\E[7m,
ri=\EM, rmacs=^O, rmcup=\E[2J\E[?47l\E8, rmir=\E[4l,
rmkx=\E[?1l\E>, rmso=\E[m, rmul=\E[m,
rs2=\E[m\E[?7h\E[4l\E>\E7\E[r\E[?1;3;4;6l\E8, sc=\E7,
setab=\E[4%p1%dm, setaf=\E[3%p1%dm, sgr0=\E[m, smacs=^N,
smcup=\E7\E[?47h, smir=\E[4h, smkx=\E[?1h\E=, smso=\E[7m,
smul=\E[4m, tbc=\E[3g, u6=\E[%i%d;%dR, u7=\E[6n,
u8=\E[?1;2c, u9=\E[c,
That contains information about box drawing characters, code sequences generated by function keys, various cursor movement sequences, and so on.
You can find out more about X/Open Curses (v4.2) in HTML. However, that is officially obsolete, superseded by X/Open Curses v7, which you can download for free in PDF.
If you're using write just so you have low-level cursor control, I think you are using the wrong tool for the job. There are command codes for many types of terminal. VT100 codes, for example, are sequences of the form "\x1b[...", but rather than sending raw codes, you'd be much better off using a library like ncurses.
Need to know how to print a Time variable in Ada. I assume there is no portable way because Time is implementation defined. I've already seen the GNAT.Calendar.Formatting package available under GNAT, I'd also be interested in a GHS for VME.
See package "Ada.Calendar.Formatting" function "Image" for Ada2005. If you have an Ada95 compiler you could and this package isn't available, try my implementation from here
This was written using GNAT 3.15p, so pretty old.
Sure, time output can be portable, Ada.Calendar contains standard functions that extract the components of a time value, so it's straightforward to put together your own conversion package.
For example, here's one. One just needs to either create a minor addition to create a "Formatted_Time" record for a given Time value (see the package's Get_Time() function for guidance), or make Main_Formatter() visible in the package spec.
Generally what I do is use Calendar.Split and then do a 'image on the parts I care about.
Here's an example that displays the date and time using the GNAT.Calendar.Time_IO package:
with ada.calendar;
with gnat.calendar.time_io;
procedure display_time is
begin
gnat.calendar.time_io.put_time(ada.calendar.clock, "Date: %Y/%m/%d Time: %H:%M:%S");
end display_time;
Date/time format options are available here:
https://en.wikibooks.org/wiki/Ada_Programming/Libraries/GNAT.Calendar.Time_IO