Help to understand part of algorithm in excel

coinscashout

jr. member

Activity: 45

Merit: 4

Thank you very much for your help

achow101

staff

Activity: 3458

Merit: 6793

Just writing some code

Quote from: coinscashout on August 30, 2015, 05:17:07 PM

I'm keen on understanding how the algorithm works. I've understood bits and bobs via https://www.youtube.com/watch?v=UZBZPOEVyJA and the excel file associated with it.

I am struggling to understand what these values mean in excel however:

MID(HEX2BIN(IF(ISERROR(MID(D13,LEN(D13),1)),0, MID(D13,LEN(D13),1)),4),4,1)

I get what hex2bin means (hex to binary) but what does the rest actually mean? Am I right in assuming "mid" would mean middle range or something similar.

Please help if you have a better understanding of the formula and bitcoin algo

MID is actually taking a substring with these parameters

Code:

MID( text, start_position, number_of_characters )

So lets start with

Code:

IF(ISERROR(MID(D13,LEN(D13),1)),0, MID(D13,LEN(D13),1))

This chunk of code means

Code:

If the last character of D13(substring of 1 character starting at the character at the length of D13) is an error, then output is 0. Otherwise the output is the last character

The output of the if statement goes into HEX2BIN which takes paramters

Code:

HEX2BIN(number, [places])

where number is the number and places is the number of characters to use. In this case, 4.

The remaining code comes out to mean

Code:

The substring of the output of the 4 character hex to bin conversion of the last character of D13 or 0 starting at the 4th character with a size of 1 character.

Basically it is taking the last character of the binary output of either the last character of D13 or 0.

coinscashout

jr. member

Activity: 45

Merit: 4

I'm keen on understanding how the algorithm works. I've understood bits and bobs via https://www.youtube.com/watch?v=UZBZPOEVyJA and the excel file associated with it.

I am struggling to understand what these values mean in excel however:

MID(HEX2BIN(IF(ISERROR(MID(D13,LEN(D13),1)),0, MID(D13,LEN(D13),1)),4),4,1)

I get what hex2bin means (hex to binary) but what does the rest actually mean? Am I right in assuming "mid" would mean middle range or something similar.

Please help if you have a better understanding of the formula and bitcoin algo

Topic: Help to understand part of algorithm in excel (Read 925 times)