Error running Readme example

[camdenhu]

Hi, I am encountering this error when running the example in Readme. The error is thrown when I run: fforma_fit <- train_metalearning(ts_dataset) Error in match.fun(features[i]) : 'features[i]' is not a function, character or symbol

Here is my sessionInfo:

R version 3.5.1 (2018-07-02) Platform: x86_64-redhat-linux-gnu (64-bit) Running under: CentOS Linux 7 (Core)

Matrix products: default BLAS: /usr/local/lib64/R/lib/libRblas.so LAPACK: /usr/local/lib64/R/lib/libRlapack.so

locale: [1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8 LC_MONETARY=en_US.UTF-8
[6] LC_MESSAGES=en_US.UTF-8 LC_PAPER=en_US.UTF-8 LC_NAME=C LC_ADDRESS=C LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C

attached base packages: [1] stats graphics grDevices utils datasets methods base

other attached packages: [1] future_1.14.0 fforma_0.0.1

loaded via a namespace (and not attached): [1] Rcpp_1.0.2 urca_1.3-0 pillar_1.4.2 compiler_3.5.1 iterators_1.0.12 tsfeatures_0.1 tseries_0.10-47
[8] tools_3.5.1 xts_0.11-2 digest_0.6.21 memoise_1.1.0 nlme_3.1-137 tibble_2.1.3 gtable_0.3.0
[15] lattice_0.20-35 pkgconfig_2.0.3 rlang_0.4.0 Matrix_1.2-14 foreach_1.4.7 rstudioapi_0.10 curl_3.2
[22] yaml_2.2.0 parallel_3.5.1 Mcomp_2.8 dplyr_0.8.0.1 globals_0.12.4 xgboost_666.6.4.1 lmtest_0.9-37
[29] grid_3.5.1 nnet_7.3-12 forecast_8.9 tidyselect_0.2.5 data.table_1.12.4 glue_1.3.1 listenv_0.7.0
[36] R6_2.4.0 future.apply_1.3.0 ggplot2_3.2.1 purrr_0.3.2 TTR_0.23-5 magrittr_1.5 codetools_0.2-15
[43] scales_1.0.0 assertthat_0.2.0 quantmod_0.4-15 timeDate_3043.102 colorspace_1.4-1 fracdiff_1.4-2 quadprog_1.5-7
[50] stringi_1.4.3 lazyeval_0.2.2 munsell_0.5.0 crayon_1.3.4 zoo_1.8-6