# Rmarkdown can't knit ur.df function

Hi, and welcome!

It's a good practice to include a reproducible example, called a reprex to attract more and quicker answers.

I used a `help` example which renders in the console

``````library(urca)
data(nporg)
gnp <- na.omit(nporg[, "gnp.r"])
df.gnp <- ur.df(gnp, type="trend", lags=4)
summary(df.gnp)
#>
#> ###############################################
#> # Augmented Dickey-Fuller Test Unit Root Test #
#> ###############################################
#>
#> Test regression trend
#>
#>
#> Call:
#> lm(formula = z.diff ~ z.lag.1 + 1 + tt + z.diff.lag)
#>
#> Residuals:
#>     Min      1Q  Median      3Q     Max
#> -42.492  -9.887   0.912   9.861  25.634
#>
#> Coefficients:
#>             Estimate Std. Error t value Pr(>|t|)
#> (Intercept) -2.71394    4.63380  -0.586    0.561
#> z.lag.1     -0.02785    0.04211  -0.661    0.511
#> tt           0.61613    0.38509   1.600    0.116
#> z.diff.lag1  0.33761    0.14502   2.328    0.024 *
#> z.diff.lag2  0.02606    0.15108   0.173    0.864
#> z.diff.lag3 -0.05841    0.15099  -0.387    0.701
#> z.diff.lag4 -0.19280    0.15010  -1.284    0.205
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#>
#> Residual standard error: 15.31 on 50 degrees of freedom
#> Multiple R-squared:  0.3033, Adjusted R-squared:  0.2197
#> F-statistic: 3.628 on 6 and 50 DF,  p-value: 0.004582
#>
#>
#> Value of test-statistic is: -0.6614 4.2327 3.2833
#>
#> Critical values for test statistics:
#>       1pct  5pct 10pct
#> tau3 -4.04 -3.45 -3.15
#> phi2  6.50  4.88  4.16
#> phi3  8.73  6.49  5.47
``````

Created on 2019-12-18 by the reprex package (v0.3.0)

``````
and in a knitted Rmd file

---
title: "urca"
author: "Richard Careaga"
date: "12/18/2019"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk\$set(echo = TRUE)
``````
``````library(urca)
data(nporg)
gnp <- na.omit(nporg[, "gnp.r"])
df.gnp <- ur.df(gnp, type="trend", lags=4)
summary(df.gnp)
``````

equally well.