Advice on memory block operations sought

Getting Started
1

Hi all,

I’m pretty new to memory blocks. I managed to set up a memory block and populate it with two strings in a row&column pattern like this

. S T R I N G A .
S . . . . . . . .
T . . . . . . . .
R . . . . . . . 
I . . . . . . . .
N . . . . . . . .
G . . . . . . . .
B . . . . . . . .
. . . . . . . . .   // <- for diagonal sums
. . . . . . . . .  // <- for weighted diagonal sums

Now what I want to achieve is a 1 where column and row have the same letter

. S T R I N G A .
S 1 0 0 0 0 0 0 .
T 0 1 0 0 0 0 0 .
R 0 0 1 0 0 0 0 .
I 0 0 0 1 0 0 0 .
N 0 0 0 0 1 0 0 . 
G 0 0 0 0 0 1 0 .
B 0 0 0 0 0 0 0 .
. 0 0 0 0 0 0 0 6  // <- for diagonal sums
. . . . . . . . .  // <- for weighted diagonal sums

For the weighted diagonal sums each row has a weight multiplier:

. S T R I N G A .
S 1 0 0 0 0 0 0 .  // *1
T 0 1 0 0 0 0 0 .  // +1
R 0 0 1 0 0 0 0 .  // +1
I 0 0 0 1 0 0 0 .  // +1
N 0 0 0 0 1 0 0 .  // +2
G 0 0 0 0 0 1 0 .  // +3
B 0 0 0 0 0 0 0 .  // +5
. 0 0 0 0 0 0 0 6  // <- for diagonal sums
. 0 0 0 0 0 0 0 9  // <- for weighted diagonal sums

How would I most efficiently do this?

TiA

Markus

2

Ok, I now have

[code]
for col as integer = 1 to LineLength-1
for row as integer = 1 to 10

  if mb.StringValue(col, 1) = mb.StringValue( row * LineLength , 1 ) then
    mb.StringValue( col + row*LineLength, 1 ) = "1"
  else
    mb.StringValue( col + row*LineLength, 1 ) = "0"
  end if
  
next row

next col[/code]

which seems to work but I have the suspicion there is a more elegant solution …

3

Yes, that’s basically it. But I wonder why you didn’t choose a multi-dimensional array instead? If your goal is raw speed, this will be faster, but for convenience, an array is better.

If your goal is raw speed, there are ways to make this code faster too.

4

Yup, speed is why I’m trying my hand at memoryblocks. I already have multi-dimensional arrays.

I feel there are better ways to do this (like get/set values, compare them, add them up) but it is still very much trial and error for me, like in this pseudo code

Mb.booleanvalue = ( mb.stringvalueA = mb.stringvalueB)

5

Use a Ptr to the MemoryBlock, then get and set Byte values. I assume 0 or 1 are just flags, so maybe something like this:

dim p as Ptr = mb
dim lastCol as integer = LineLength-1
for col as integer = 1 to lastCol
    for row as integer = 1 to 10
      
      dim rowIndex as Integer = row * LineLength
      if p.Byte(col) = p.Byte(rowIndex) then
        p.Byte(col + rowIndex) = 1
        // Assuming you started with a new MemoryBlock, you wouldn't need the Else
      end if
      
    next row
  next col
6

Thanks Kem, will try it when I’m back at my computer (I need Xojo on iPad!)