What are some free online flow chart tools? - private

Can somebody tell me of a tool that helps draw a flow chart online (to collaborate) but not make it public. I did see free, cheap or open source UML and Visio-like tool that talks of gliffy but it makes charts public in the free mode.

Eh... I'd just use vim + graphviz + git, but that's just me.

This was recommended to me: Web Sequence Diagrams.
http://www.websequencediagrams.com/
HTH

Bumping an old Q - but:
Have found this one to be very nice for ASCII flow charts:
http://www.asciiflow.com
Some highlights:
Select area and drag it around.
Write text.
Select area copy and paste it anywhere.
Export / Import.
Public edit and read only links.
Downside:
Do not support drawing by key-board.

Here is a free online tool:
https://ludoaubert.github.io/linkedboxdraw/README.html
You can start by reading the README. One key principle is that you keep your info private, it never gets uploaded.
For reverse engineering SQL schemas, of course the reverse engineered diagram will look a lot better if foreign keys are implemented :)
https://ludoaubert.github.io/linkedboxdraw/table_edit_ti.html

Related

F# Priority Queue

I have tried to use this snippet of code
https://code.msdn.microsoft.com/windowsdesktop/Net-Implementation-of-a-d3ac7b9d
to implement a heap-based implementation of Prim's algorithm to solve the Minimum Spanning Tree (MST) problem in a non-directed connected graph.
after a few iterations, i find that the heap/priority queue is not well maintained anymore.
that is the head of the PriorityQueue doesn't have the lowest Key in the Heap.
PQ 0 [-7230, 309]
...
PQ 146 [-7277, 308]
Has anyone use this code and experienced similar problems ?
I can post a link on GitHub if anyone would be looking at it
My needs are for a heap datastructure which supports deletion of an element in the middle. It looks like Fsharpx.collections doesnt have such a data structure.
does anybody know a good implementation available somewhere ?
thanks
Recently, I ported a MaxHeap from PLINQ to F# here and made it MinHeap. It is array-based and performs much better than any "pure functional" alternative.
However, after a lot of benchmarking, I found that SortedDeque based on just a simple sorted circular buffer performs significantly better on most use cases even when I need to add or delete in the middle.
My answer is inspired by V.B. but here it is in full
I have used another library than FSharpx.collections, it is called
Spreads
read that page for details and instructions.
SortedDeque is the data structure i need for this problem.
I used the same code, just changing from the microsoft blog page code to the library functions and found the good result, so it is indeed some bug in the microsoft blog page code
PS. this spreads library has been designed to format financial data for quantitative analysis and i'm happy i found it !!! IT looks like this library is rather recent and thats why its not on top of Google's search or referenced in any other SO question (or if it is i didn't see it)
FSharpx.Collections is of no use for that problem as you can see from that discussion heap issue in FSharpx.Collections

Delphi histogram component?

Does it happen that no one ever needs histogram in Delphi ?
Google gave me a bunch of half-baked code snippets. But it means that each time you need one - you have to invent one more ad hoc bycicle.
Torry mostly told me about some very expensive closed source Math Statistics or Financial packages, that as a subproduct have histograms. But they are very expensive and since you have no source code, each time you install update onto IDE/RTL/VCL you're probably screwed, until the vendor would make (soon ? ever?) updated packages. Given thatvendor is still does exists.
S.O. told me nothing, nil.
For what i found...
Mitov.com provides some histograms in PlotLab. which told to be free for non-commercial. Alas, it is again closed-source, and if the Histogram - quite fancy let's admit -is the onlything i need from it - why pay the whole price ?
One more example http://DSpatial.sf.net
Just few years ago i used it in Delphi 5, but even then i felt the author is loosing interest in the project. I made few enhancement, fixed some bugs, he merged them and that's all. The component was not very useful and lacked upon features, yet better than nothing. Now the project seems to be completely dead. Good old days, etc. But i do not want them back :-)
And Stack Overflow seemingly carries no single question about it. But maybe just no one bothered to create topic, after search found nothing ? I mean, Delphi was created for database access, histograms are one of basic ways to visualize data, and no one crosses them ? Something with nice style, with rich mouse tooltip like in HTML/CSS/JS on http://www.moskva.fm/stations/FM_95.2 ?
Or is this too domain-related and not ever possible to have good abstraction ?
TChart is a control that ships with most versions of Delphi. TChart can be used to make histograms (bar charts) in style. The following give you some ideas about how to use it: http://www.digitalcoding.com/tutorials/delphi/Simple-steps-to-create-Delphi-chart.html and http://delphi.about.com/od/adptips2006/qt/chart_selectbar.htm .
If you need something with code, google the pages at delphiforfun.org/programs/oscilloscope.htm . These are not controls. The oscilloscope article has a histogram with source. Some of the other projects at the site have other histogram graphs with source..not elegant but useful and free. Use them as a template to make your own control.
The link at http://delphiforfun.org/programs/Math_Topics/probability_distributions.htm shows how to make your own statistics displays with "histograms." This example makes use of TChart.
Here is some more stuff to try I found looking at my resource file:
http://wiki.lazarus.freepascal.org/TAChart, http://members.home.nl/mvanwesten/en_lazarus.html , http://www.martinole.org/TAChart.html ...some of these are GPU components that supposedly work with some versions of Delphi. Perhaps this is your lucky day as there is some source code. The first and third listed probably will work reasonably for histograms. You may have to write your own statistics algorithms.
Found this thread while doing some searching. The ImageEn component suite has a THistogramBox component. It's the NOT prettiest thing in the world, but it's the only one I've found so far.
http://www.imageen.com
I came across a histogram example in a gdiplus package available for download from code central. I don't know if it will do what you need but when I saw it I remembered your SO question.
HTH.
If you were using firemonkey, you could just created a series of TRectangles in series. They can be made unclickable by turning hittest off. Or is that too easy and straightforward?

Any Delphi trending controls available

I need a control to add data trending to my application. Is anything available or do I need to use a graphing control and add my own trending features?
Trending is typically an included feature in 3rd party charting components (at least the ones i've seen) but it might be called something else such as linear regression or possiblly something like "least squares*." You should definitely not need to roll your own, unless you think it would be fun. ;-)
Google-ing for "Delphi Chart Regression" will turn up some interesting links.
(* Least squares is typically the method used to establish a trend line from a data set.)
In your shoes, I'd use the stats and charting tools from http://www.lohninger.com/delfcomp.html. It may be a bit more low-level than you want, but I've been very happy with this guys tools (which are reasonably priced, IMO, and, as I recall, can be downloaded for free on a trial basis...)
Check out the curvefit example (comes with an exe demo so no compiling or installing is necessary) here: http://www.lohninger.com/examples_part1.html It'll show you the kinds of charting as well as curve fitting. It's very instructive.
Try JvChart from the JEDI JVCL. If you don't like it, let me know, because I wrote most of it, and I always like to know what people think. It can do static and scrolling displays, and it is very easy to add a few lines and plot some data. A demo app is included in the JVCL\examples\JvChart folder.
There is also TJvSimScope, which is like an oscilloscope and is optimal for fast-scrolling charts showing data which changes on a per-second basis.
JVCL is open source and free
Look for TChart component on your component palette. If your Delphi version has it, then look for demo that uses it.

Draw and manipulate shapes at run time

What's the best way to draw shapes interactively at run time using Delphi? I need to be able to select, drag and resize the shapes. This will be used to mark up existing images and documents.
This looks like a good starting point, but I'm wondering if there's a more complete library (preferably free) available that will save some time.
Update:
If you're going with a custom solution from scratch, I've seen another example on Delphi Central that might be an even better starting point.
I will recommend you, read some links on my site. Are explained and all the source code is available; You can see and get some usefull for you.
Plugin system in Delphi - Part 2
Not directly what you need, is a plugin system for Delphi. But all the samples are based on a drawing tool that uses Shapes (Creating, selecting, resizing). You can review the code and extract what you need.
Sample manipulating of "Maps and Figures"
Sample of how to create, select and move components at runtime (in this case with TImage).
- Select shapes visually: Shows different ways to select shapes visually.
The web is in Spanish, but you can generate an authomatic translation on the web itself.
Anyway the code is commented.
Regards.
Excuse-me for my bad english.
One freeware option would be TssControlSizer. Just change the "control" property to the control you want to manipulate resize/move.
Not sure if you've moved on now with this Bruce but if you haven't, it might be worth looking at TMS Components Diagram Studio - it's certainly cheap, and looks quite powerful from the demo.
I would use Flex Graphics (commercial, $499 for one developer, with sources, $1500 for site-license, with source code). When I bought it, it was a lot less than that. So I guess, I wouldn't pay that now. It's a lightweight 'drawing/cad' package.
But as I already own it, I could import a page from the original document as an image, perhaps rendered in PNG or WMF, and then mark it up with lines, etc.
You could think of it as a light "cad" package. It has most primitive shapes, and you can easily create your own new objects or shapes in Delphi classes, that could be "smart shapes" like the ones in Visio.
http://www.flex-graphics.com/
Another commercial component set that I have heard only good things about is TRichView. They have a TRichViewEdit that looks like you could emulate a document markup environment easily with it.
Please check here:
TCAD -2d graphics component for delphi
http://www.codeidea.com
wish can help you.

Does anyone know resources for LaTex

I want to use LaTex to write equations faster and if it is possible to export the result as a png or jpg so that it can be used on a website.
Wikipedia (and its opensource wiki engine) uses LaTeX for that, maybe there are some resources available (at least in the code, as it is opensource).
Your question is very broad. You could start with Amazon's List of Latex Books.
You might want to investigate the StackExchange site mathoverflow.net solution - you can read about here. It uses jsMath which supports a lot of LaTeX syntax.
Assuming you already know a little LateX and your primary goal is to get images, a good high-level tool is mathTeX; there are even public servers that will convert to images for you.
If you want to do everything yourself, all the tools use dvipng at bottom.
I like both MathBin.net and Roger's Online Equation Editor. The latter lets you control the quality of the output. See also this question.
try this: http://hausheer.osola.com/latex2png
Here is a small symbol reference for LaTeX. If you are looking for something more as a general introduction, you can look at "The Not So Short Introduction To LaTeX2e". If you use Inkscape, there is built in support for rendering LaTeX and there are also extensions that do the same. You can read some commentary about it here. There are also things like LaTeX to HTML converters; However, at the time I was looking at them, they were somewhat limited in what formulas they could display.
I taught myself LaTeX using the wikibook. It's fairly comprehensive as an initial guide. I've since bought The LaTeX Companion, which is a more advanced guide to in depth typesetting in LaTeX
I use http://www.artofproblemsolving.com/LaTeX/AoPS_L_TeXer.php when I need a quick equation for a web site.
There are packages that will automatically produce images from LaTeX source, but these are often either buggy or used incorrectly. Many people install them on their blogs, for example, and the images show up if you visit the blog directly but they don't show up if you view the page via a blog reader. I'm not saying these problems can't be fixed. They can, but it often takes a few tries.
I prefer just to make a gif and stick it in the page. It's low tech and reliable.
One more tip: it's a good idea to put the LaTeX source in the alt tag of the image. This helps people using screen readers. It helps you too if you need to modify the equation later.
Detextify is a great site that lets you draw a symbol, and it will pop up a list of latex commands that may match your drawing. It's quite accurate! http://detexify.kirelabs.org/classify.html

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