用來定義、優化和模擬數學表達式計算：Theano
Theano 是一個 Python 庫，用來定義、優化和模擬數學表達式計算，用于高效的解決多維數組的計算問題。Theano的特點：緊密集成Numpy；高效的數據密集型GPU計算；高效的符號微分運算；高速和穩定的優化；動態生成c代碼；廣泛的單元測試和自我驗證。自2007年以來，Theano已被廣泛應用于科學運算。theano使得構建深度學習模型更加容易，可以快速實現多種模型。
Theano is a Python library that allows you to define, optimize, and evaluate mathematical expressions involving multi-dimensional arrays efficiently. Theano features:
1）tight integration with NumPy – Use numpy.ndarray in Theano-compiled functions.
2）transparent use of a GPU – Perform data-intensive calculations up to 140x faster than with CPU.(float32 only)
3）efficient symbolic differentiation – Theano does your derivatives for function with one or many inputs.
4）speed and stability optimizations – Get the right answer for log(1+x) even when x is really tiny.
5）dynamic C code generation – Evaluate expressions faster.
6） extensive unit-testing and self-verification – Detect and diagnose many types of mistake.
Theano has been powering large-scale computationally intensive scientific investigations since 2007. But it is also approachable enough to be used in the classroom (IFT6266 at the University of Montreal).