# Concepts

**URL:** https://discourse.pumas.ai/c/concepts/19.md

[Latest](https://discourse.pumas.ai/latest.md) · [Categories](https://discourse.pumas.ai/categories.md)

---

## [About the Concepts category](https://discourse.pumas.ai/t/about-the-concepts-category/85)

<div class="topic-metadata">

**Author:** [@vijay](https://discourse.pumas.ai/u/vijay)\
**Replies:** 0

</div>

---

## [Can you compare two models with the same dataset but use DV vs LNDV?](https://discourse.pumas.ai/t/can-you-compare-two-models-with-the-same-dataset-but-use-dv-vs-lndv/1151)

<div class="topic-metadata">

**Author:** [@engie](https://discourse.pumas.ai/u/engie)\
**Replies:** 3\
**Last updated:** [March 8, 2025, 8:44pm UTC](https://discourse.pumas.ai/t/can-you-compare-two-models-with-the-same-dataset-but-use-dv-vs-lndv/1151 "2025-03-08T20:44:36Z")

</div>

This might be a very dumb question, but is it valid to compare a 2 compartment model using DV as an input versus a TMDD model using LNDV? As in, are the delta OFV values comparable to determine which one is better? Or wo…

---

## [Addressing Unsuccessful Minimization](https://discourse.pumas.ai/t/addressing-unsuccessful-minimization/642)

<div class="topic-metadata">

**Author:** [@adunn34](https://discourse.pumas.ai/u/adunn34)\
**Replies:** 7\
**Last updated:** [September 26, 2023, 12:26pm UTC](https://discourse.pumas.ai/t/addressing-unsuccessful-minimization/642 "2023-09-26T12:26:20Z")

</div>

Does anyone have recommendations on steps you should take when your model fit is unable to successfully minimize? I saw the prior feed on failed minimization (Successful minimization:) and looked at my ft.optim, but I am…

---

## [Non linear kinetics flow dependant](https://discourse.pumas.ai/t/non-linear-kinetics-flow-dependant/327)

<div class="topic-metadata">

**Author:** [@monika](https://discourse.pumas.ai/u/monika)\
**Replies:** 11\
**Last updated:** [April 20, 2020, 7:20am UTC](https://discourse.pumas.ai/t/non-linear-kinetics-flow-dependant/327 "2020-04-20T07:20:06Z")

</div>

Hello, can anyone help me with code this is a multi compartment model and the clearance is concentration dependant and also they have given a proportionality constant (a) for the changes in plasma concentration, which i …