I can’t reproduce this:

```
julia> coxph(Surv(df.duration, df.event) ~ df.x1 + df.x2, df)
ERROR: MethodError: no method matching ~(::SurvivalAnalysis.IntSurv, ::Vector{Float64})
```

That said, I’m not sure I understand what you are doing - you seem to be mixing `SurvivalAnalysis`

with `Survival`

, two packages which implement similar (and overlapping) functionality, but aren’t meant to be used together as far as I know. `SurvivalAnalysis`

doesn’t implement a Cox-PH model at present, and `Surv`

is a type defined in the `Survival`

package.

In `Survival`

, a Cox-PH model is fit as follows:

```
julia> df.event = EventTime.(df.duration, df.event .== 1);
julia> coxph(@formula(event ~ x1 + x2), df)
StatsModels.TableRegressionModel{CoxModel{Float64}, Matrix{Float64}}
event ~ x1 + x2
Coefficients:
─────────────────────────────────────────────
Estimate Std.Error z value Pr(>|z|)
─────────────────────────────────────────────
x1 0.474264 0.590107 0.803691 0.4216
x2 -0.310167 0.497345 -0.623646 0.5329
─────────────────────────────────────────────
```

See the docs here:

https://juliastats.org/Survival.jl/latest/getting_started/#Fitting-the-model

In `Survival`

, the syntax is:

```
f = kaplan_meier(@formula(Surv(Y, D) ~ 1), data)
```

However as I said above there’s no `coxph`

method.

Also note that your syntax for calling the fitting procedure is off - the first arugment should be a formula, which you either create by using the `@formula`

macro or by putting together `Term`

objects yourself, not by passing the actual data directly.

I recommend you read the docs of both `Survival`

and `SurvivalAnalysis`

to understand the correct syntax and the functionality of each package, and maybe the docs of `StatsModels`

as well to understand how `@formula`

works.