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What is the logic of the epoch? For example, 1 time, 2 times, etc. I just do not know what else is working to give better results than I know.

Shayan Shafiq
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Developer
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2 Answers2

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There are two terms which relate to the number of examples while learning. Epoch and iteration. During each epoch, you feed all the examples in your training set and update the network. You can feed the data simultaneously, not for large-scale tasks, or batch by batch. Each turn you pass each batch is called iteration. Consequently, each epoch may have multiple iterations. The reason we have to pass the data multiple times is that we don't know the height of each local optimum along each axis, feature. Consequently, we use a learning rate to limit our steps to small ones and take multiple steps to get close to the desired point.

Due to the request of one of our friends I add the explicit definitions:

  • Epoch: It means how many times the entire dataset has been passed through the network.
  • Iteration: It means for each epoch, how many times you have passed the chunks of the dataset. These chunks of data are called batch and the number of times you pass them through the network is called the number of iterations.
Green Falcon
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  • The difference between epoch and iteration definition should be made more readable by suitable formatting – DuttaA Aug 04 '18 at 13:54
  • @DuttaA I'm open to criticism, which part you think is not readable? – Green Falcon Aug 04 '18 at 14:09
  • I have understood the answer, i just think many users who does not have a pre-emptive knowledge of the difference would not understand the difference...like iterations are over batches or examples or epochs...whereas epochs are over entire training set no matter the method....the difference should be stated in bold like : epoch : iterations or any form seen suitable – DuttaA Aug 04 '18 at 14:12
  • (@media )Thanks, can we say: Epoch: a complete tour.iteration: fragmented, full tour of one. – Developer Aug 05 '18 at 06:30
  • @Engin I didn't understand the last part. – Green Falcon Aug 05 '18 at 06:51
  • @Media iteration: for example, the data is part of 10 parts and one of this part completes: 1 itertation.2 completes 2 : itertation. ( I meant it) – Developer Aug 05 '18 at 07:14
  • @Engin If I've gott the point correctly, yes. – Green Falcon Aug 05 '18 at 09:20
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In a simple way, Epoch is an iteration. For example, in k-means clustering, in each epoch you get better clusters. enter image description here

After a successful epoch the clusters in (a) are approximated better to clusters in (b).