difficulty over time data?

[mndrix]

Is there downloadable data available showing the Bitcoin difficulty over time.  I'm imagining a CSV file with block number (every 2016) and difficulty.  Something like:

  0,1
  2016,1
  ...
  96768,12252.03471156

Certainly something like this exists, but the closest I've seen is Difficulty vs Time Graph, which actually shows a Price vs Time graph

[mndrix]

Soon after posting, I realized that blockexplorer.com shows the difficulty for each block.  Worst case, I'll go through each 2016th block and note the difficulty and put it in a Google Spreadsheet and post the link here.  If someone's already consolidated the data in one place, let me know.

[m0mchil]

http://nullvoid.org/bitcoin/difficultiez.php

[mndrix]

Thanks m0mchil.

For those interested, below is a logarithmic graph of difficulty over time.  Time is represented by block number.  The data fits the following equation with R^2 of .997:

  difficulty = .00165*exp( blockNumber * .000163 )

Might be handy for those calculating the future value of their expensive GPUs

[genjix]

what's the correlation between that graph and the equation you worked out? not sure how to do it for quadratic curves..

[mndrix]

what's the correlation between that graph and the equation you worked out? not sure how to do it for quadratic curves..

The best way I've found is to use Wolfram Alpha.  Here's the equation and correlation covering the last 4 difficulty adjustments.

[mndrix]

I've updated the above chart with the new difficulty as of block 98784

[wumpus]

Is there a block number <-> datetime mapping available?

[mndrix]

Is there a block number <-> datetime mapping available?

The link given above (http://nullvoid.org/bitcoin/difficultiez.php) includes timestamps for all the blocks in which difficulty changed.  For arbitrary blocks, you can use Block Explorer.  For example, block #42000 was generated at 2010-02-22 22:39:33

Would it be helpful to you to have a chart like the one above but with a real time x-axis?  I could generate one fairly easily.

[wumpus]

Would it be helpful to you to have a chart like the one above but with a real time x-axis?  I could generate one fairly easily.

Yes, that's exactly why I asked. I'd personally prefer the x-axis to be time. Although in theory the block generation rate should be fixed, so the picture shouldn't be very different.

[mndrix]

Here is the same data with the x-axis showing calendar time:

[wumpus]

Thanks! As expected, it indeed looks almost the same as the block#-based one. Interesting.

[mndrix]

I've updated the above charts to reflect recent difficulty changes.  I'm using the historic difficulty data from http://blockexplorer.com/q/nethash

[foxmulder]

is the any new updated chart for future estimation(range to 1 month-1 year)?

[Pieter Wuille]

I don't make any prediction about the future, but you may see some useful patterns on my site with network speed and difficulty graphs: http://bitcoin.sipa.be

[mndrix]

I'm no longer updating my graphs above because sipa's are better