# Categorical Covariates

**URL:** <https://discourse.pumas.ai/t/categorical-covariates/345>\
**Category:** model-syntax\
**Created:** [May 15, 2020, 4:53pm UTC](https://discourse.pumas.ai/t/categorical-covariates/345 "2020-05-15T16:53:27Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![PavanVaddady](https://avatars.discourse-cdn.com/v4/letter/p/bb73d2/32.png) [@PavanVaddady](https://discourse.pumas.ai/u/PavanVaddady)\
**Post date:** [May 15, 2020, 4:53pm UTC](https://discourse.pumas.ai/t/categorical-covariates/345/1 "2020-05-15T16:53:28Z")

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Hi,

Can you help me understand the syntax on how to set up categorical covariates as part of the model? For example, I am looking for conditional statements:

IF(GENDER=MALE) xxx  
IF(GENDER=FEMALE) xxx etc

Thanks,  
Pavan.

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**Author:** ![Vaibhavdixit02](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.pumas.ai/vaibhavdixit02/32/86_2.png) [@Vaibhavdixit02](https://discourse.pumas.ai/u/Vaibhavdixit02)\
**Post date:** [May 16, 2020, 10:03am UTC](https://discourse.pumas.ai/t/categorical-covariates/345/2 "2020-05-16T10:03:45Z")

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Hi Pavan,

You would want to modify this according to your use but here are a few examples:

In the `@pre` block in case the covariate coefficient on the population value has an additive effect. You can also parameterize that as having a proportional effect by replacing the additions by a multiplication where needed.

```auto
beta0 = tvbeta0 + (GENDER=="MALE") * maleparam + (GENDER=="FEMALE") * femaleparam

```

OR

```auto
beta0 = tvbeta0 
if GENDER=="MALE" 
  beta0 += maleparam 
else
  beta0 += femaleparam
end

```

OR

```auto
if GENDER=="MALE"
  beta0 += maleparam 
elseif GENDER=="FEMALE"
  beta0 += femaleparam
end

```

OR

```auto
beta0 = tvbeta0 + GENDER == "MALE" ? maleparam : femaleparam

```

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<div class="post-metadata">

**Author:** ![PavanVaddady](https://avatars.discourse-cdn.com/v4/letter/p/bb73d2/32.png) [@PavanVaddady](https://discourse.pumas.ai/u/PavanVaddady)\
**Post date:** [May 17, 2020, 9:17pm UTC](https://discourse.pumas.ai/t/categorical-covariates/345/3 "2020-05-17T21:17:33Z")

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Thanks Vaibhav. This is very helpful!

Pavan.