Great news about vectors and matrices

[Proektsoftbg]

Hello, mates!

We have some good news from the kitchen today.

Recently, we are working hard on vectors and matrices. I am eager to have them sooner and we got some partial success. Now, we can create vectors, perform some operations on them, save and display the results. To make difference from regular (scalar) variables, the program adds some little nice arrows over the names. Large vectors are processed in parallel to take full advantage from the modern hardware.

However, there is still a lot of work to do. If you use and like Calcpad, please consider ❤️ sponsoring the development on GitHub and help us to get it ready for you faster:
https://github.com/sponsors/Proektsoftbg

[Grefron]

Wow, really nice. Feels to me that vector/matrix support is the next 'big thing' for Calcpad! Keep up the great work!

[Proektsoftbg]

The next important step achieved is to access elements of vectors by index to read and write values.

In the example bellow, the last 5 elements are assigned to be the squares of the first 5 in a loop:

The "dot" operator . is used for the purpose. Indexes can be constants, variables or expressions that evaluate to a single (scalar) number. Expressions must be enclosed in brackets. Indexes are of higher priority than other operators. So that, if the brackets are missing, the next terms will fall off the index and operate on the element instead.

I also suggest that a "for" loop should be introduced:

#for i = 1:5
...
#loop

Otherwise, there is too much writing for indexing in a loop.

[Grefron]

The for-loop would be a nice addition, I also like the proposed notation.

However, I am unsure about the syntax to access the vector elements. I personally would prefer a notation in which the index is indicated between square brackets, so something like this:

a = [1; 2; 3; 4]
a[1]   '-> element 1
a[2] = a[1]  '-> a = [1;1;3;4]

In any case, using the dot may break backwards compatibility, since it is now a valid character for a variable name.

[Proektsoftbg]

Yes, this is more C-like syntax. Dot was used in old versions of MathCAD and in most programming language to access an element of a class or struct. Somehow it looks shorter to me to write a.1 instead of a[1].

This will not brake the backward compatibility. If you have a variable a.1 = 1, it will still work. So, nothing will change for old worksheets But if you define a vector a = [1;2;3], it will override all variables a.n as well as the a variable itself, if exists.

Anyway, I will play a lot more to see if this approach will not have any flows.

[jgagnonNT]

Hello, great work! It look promising, I'm looking forward to try it!
Will it be possible to access multiple value of a matrix, for exemple in Matlab if I want to assign the second line of a matrix I would write it like:
B = A(2,:)
The : would mean the whole line.
B would then be a vector.

In Matlab you can also access a range of values of a vector:
B = A(3:5)
B would then become a vector of the values in spaces 3, 4 and 5.

Those options could be useful in the future and it seems that the brackets would make it more clear than the points to access ranges.

[Proektsoftbg]

Vector initializers will include numbers, variables or expressions for the elements. But what happens if I include a vector in a vector initializer list. One option is to return an error. The other option is to expand the vector and include its elements into the sequence.

This will turn the initializer into a powerful concatenation operator. In any case there will be also a join function like: d = join(a; b; c). Of course, you will not be able to assign a vector directly to an element of another vector. But with slicing and concatenation, you will be able to assemble a new vector from other vector parts.

Matrices will be created by separating the rows with vertical bars "|", e.g: M = [1; 2; 3 | 4; 5; 6 | 7; 8; 9]
This will result in the following output:

M = ⎡1  2  3⎤
    ⎢4  5  6⎥
    ⎣7  8  9⎦

This is shorter than using nested square brackets: M = [[1; 2; 3]; [4; 5; 6]; [7; 8; 9]]

I also wonder whether to remove the semicolons ";" from the output. How about this, compared to the previous one:

For me, this is more simple, clean and "mathematical" way to display vectors and matrices rather than the "programming" way with delimiters. :)

[Proektsoftbg]

Hello friends! :)

The work on vectors runs as a high speed train that cannot be stopped. ;)

Just added a lot of new special functions only for vectors: initialization with zero, number or range, resizing, slicing, joining, sorting, lookup, norm, dot/cross product, etc.

Existing aggregate functions, like min, max, sum, average, product, mean, etc. can also work on vectors by just passing the vector, instead of a list of values. The same applies for interpolation: line and spline.

[Proektsoftbg]

Hi! I added two more types of loop blocks:

#for counter = start : end
...
#loop

and

#while condition ' , ' additional expressions
...
#loop. 

Although you can do the same with #repeat and some #ifs where needed, they have shorter and clearer syntax.#while even allows some hidden expressions to be added on the same line, divided by comments, to update counters, etc.

Isn't it better to substitute the index values instead of displaying the index variable names like above:

I think it will be clearer what we are exactly doing.

[Proektsoftbg]

Vector and matrix calculations seems to require quite a lot of work to implement. We are not some big company with large resources. Actually, Proektsoft is just me - one man army from a small but beautiful country. :)

If you use and love Calcpad and want to have them sooner, please consider donating the project on GitHub:

https://github.com/sponsors/Proektsoftbg

Many thanks to all community members that already sponsor Calcpad or support us in other ways. With your contribution, Calcpad got to be such a wonderful software. But we can do even better than this together.

[Proektsoftbg]

It seems that currently there is no much interest about vectors and matrices in Calcpad.
So, for now I will make them as far as they will work for my PhD thesis and will release them some time later in the future.

[Grefron]

Sorry to hear this, hop you're not discouraged since the work done so far on Calcpad is truly phenomenal. Personally, I would really like to see the vector and matrix functionality, but if that requires some more time, I'm perfectly fine with that!

[Proektsoftbg]

Thank you!

It is really a lot of work and will take significant amount of time. Unfortunately, bills are piling up and I cannot spend so much time on a free project. I have to focus more on other projects that pay the bills and work on Calcpad only when I find some free time. I hope you understand this.

Also, after two years, I am really starting to wonder if going FOSS had actually contributed to the project anyhow. Probably not much.

So, I am considering to freeze this repository at the current state and focus on my regular work and PhD thesis. I will probably continue to develop Calcpad for the needs of Proektsoft and our clients, but not updating and maintaining the free version anymore. It does not have any sense for me.