The following is generated using http://www.wessa.net/rwasp_grangercausality.wasp:
Summary of computational transaction
Raw Input view raw input (R code)
Raw Output view raw output of R engine
Computing time 2 seconds
R Server 'Herman Ole Andreas Wold' @ wold.wessa.net
Granger Causality Test: Y = f(X)
Model Res.DF Diff. DF F p-value
Complete model 356
Reduced model 357 -1 17.9144959720894 2.94360540545316e-05
Granger Causality Test: X = f(Y)
Model Res.DF Diff. DF F p-value
Complete model 356
Reduced model 357 -1 0.0929541667364279 0.760632773377753
My interpretation is that:
(i) Granger Causality Test: Y = f(X) p-value = 2.94360540545316e-05
The p-value is very small, thus the null hypothesis Y = f(X), X Granger causes Y, is rejected.
(ii) Granger Causality Test: X = f(Y) p-value = 0.760632773377753
The p-value is near to 1 (i.e. 76%), therefore the null hypothesis X = f(Y), Y Granger causes X, cannot be rejected.
Is my interpretation correct?
[Related to full question in Interpreting Granger causality test's results.]