Tensorboard

根据 https://github.com/tensorflow/tensorboard/blob/master/README.md 整理

Key Concepts
Summary ops: the Tensors they produce contain serialized protobufs
	tf.summary.scalar
	tf.summary.image
	tf.summary.audio
	tf.summary.text
	tf.summary.histogram
	
Tag: When you initialize a summary op, you will also give it a tag. The tag is a name for the data recorded by that op, and will be used to organize the data in the frontend Tensorboard

Event Files & LogDirs
summary.FileWriters将summary op的serialized protobufs写到logdir里
Specifically, the data is written to an append-only record dump that will have "tfevents" in the filename
TensorBoard search events file in the entire directory, and organizes it into the history of a single execution

Comparing different executions of your model
tensorboard --logdir name1:/path/to/logs/1,name2:/path/to/logs/2

Scalar Dashboard
Dragging a rectangular region on the chart will zoom in
Double clicking on the chart will zoom out

Histogram Dashboard
Each chart shows temporal "slices" of data, where each slice is a histogram of the tensor at a given step. 
timestamp最旧的在后面，最新的在前面

Distribution Dashboard
每条线代表了一个percentile随时间变化的趋势
从top到bottom，每条线代表的percentile是 [maximum, 93%, 84%, 69%, 50%, 31%, 16%, 7%, minimum]

Graph Explorer
建议使用name scopes来组织graph里的op

Embedding Projector
从checkpoint文件里读取数据